Abstract: A Fast Faraday Cup includes a group of electrodes including a grounded electrode having a through hole and a collector electrode configured with a blind hole that functions a collector hole. The electrodes are configured to allow a beam (e.g., a non-relativistic beam) to fall onto the grounded electrode so that the through hole cuts a beamlet that flies into the collector hole and facilitates measurement of the longitudinal distribution of particle charge density in the beam. The diameters, depths, spacing and alignment of the collector hole and the through hole are controllable to enable the Fast Faraday day cup to operate with a fast response time (e.g., fine time resolution) and capture secondary particles.

Abstract: A low-resolution image is displayed at higher resolution and afterimages are reduced. Resolution is made higher by super-resolution processing. In this case, the super-resolution processing is performed after frame interpolation processing is performed. Further, in that case, the super-resolution processing is performed using a plurality of processing systems. Therefore, even when frame frequency is made higher, the super-resolution processing can be performed at high speed. Further, since frame rate doubling is performed by the frame interpolation processing, afterimages can be reduced.

Abstract: A charged particle beam dump for a charged particle beam device is described. The beam dump includes an annular shaped body having an inner perimeter wall that defines an open annulus for passing of primary charged particle beamlets, the annular shaped body further having an outer perimeter wall and a bottom wall; and an annular shaped electrode provided partially above the annular shaped body having an inner perimeter side and an outer perimeter side, wherein the inner perimeter side is outside of the radius of the inner perimeter wall of the annular shaped body.

Abstract: The present invention provides a high voltage regulated DC power supply with full range 24 pulse input for ripple free output for high power RF amplifier, comprising: full range 24 pulse 3 phase 11 kV input system configured to provide uncontrolled low voltage DC bus, low input harmonics and high input power factor; a plurality of DC-DC power modules having their output connected in a series and coupled to the said DC bus voltage; each power module comprising a DC source, an inverter bridge IGBTs operating at predefined duty cycle and staggered to reduce the output ripple and output stored energy; and a combination of feed forward and feedback control circuit adapted to regulate the variations in the input line voltage and the variation in output at various load current to finally obtain ripple free high voltage output.

Abstract: An image display apparatus according to the present invention, includes a light emitter, a first panel configured to transmit light emitted from the light emitter, a second panel configured to transmit light transmitted through the first panel, and a controller configured to control emission brightness of the light emitter and at least one of transmittance of the first panel and transmittance of the second panel, based on input image data.

Abstract: An undulator for a free electron laser includes a pipe for an electron beam and one or more periodic magnetic structures extending axially along the pipe. Each periodic magnetic structure includes a plurality of magnets and a plurality of passive ferromagnetic elements, the plurality of magnets being arranged alternately with the plurality of passive ferromagnetic elements in a line extending in an axial direction. Each of the plurality of magnets is spatially separated from the pipe, and each of the passive ferromagnetic elements extends radially from an adjacent magnet towards the pipe. A spacer element may be provided between the magnets and the pipe to provide radiation shielding for the magnets and/or cooling for the pipe.

Abstract: A coaxial amplifier having at least one electron beam is provided. The amplifier may include a conductive rod, a plurality of parallel discs on the rod, a cathode array for producing at least one electron beam. When a plurality of electron beams are formed they are arranged in an annular configuration around said rod and disks, and directed along said rod and coaxially thereof. A first waveguide may apply electromagnetic wave energy to one end of said disc and rod assembly to induce propagation of said energy along said assembly. A second waveguide may extract the amplified electromagnetic energy from the other end of the disc and rod assembly.

Abstract: A microwave wave generator device with oscillating virtual cathode, with axial geometry, includes at least one first reflector positioned in a cylindrical waveguide downstream of a thin anode, positioned at the entrance of the cylindrical waveguide, between a cathode and the cylindrical waveguide. The device further includes a tight magnetic ring of width (LM) along the longitudinal axis (z), positioned externally around the cylindrical waveguide, between the thin anode and the first reflector.

Abstract: The present disclosure provides a method for controlling brightness compensation for pixel units of a display device, comprising: driving white subpixels in the pixel units to compensate the pixel units for the brightness according to predetermined pixel units whose brightness is to be compensated for in the display device and compensating grayscale voltages corresponding to the brightness of the pixel units to be compensated.

Abstract: In an avalanche photodiode provided with a substrate including a first electrode and a first semiconductor layer, formed of a first conductivity type, which is connected to the first electrode, the configuration is in such a way that, at least an avalanche multiplication layer, a light absorption layer, and a second semiconductor layer having a bandgap that is larger than that of the light absorption layer are layered on the substrate; a second conductivity type conductive region is formed in the second semiconductor layer; and the second conductivity type conductive region is arranged so as to be connected to a second electrode. With the foregoing configuration, an avalanche photodiode having a small dark current and a high long-term reliability can be provided with a simple process.

Abstract: A light source apparatus includes a discharge lamp including a light-emitting container having a cavity in which a discharge medium is enclosed, and a pair of electrodes disposed such that respective tip portions thereof oppose each other in the cavity, and a driving unit that supplies a driving current to the pair of electrodes. The driving current is generated by modulating amplitude of alternating current having a frequency not lower than 1 kHz and not higher than 10 GHz, such that a first section and a second section in which the amplitude is smaller than in the first section are alternately repeated.

Abstract: An oscillating field particle accelerator and a method of reducing beam divergence in the particle accelerator are provided. The particle accelerator includes an intermediate electrode disposed within the particle accelerator between a source of charged particles and a second electrode of the particle accelerator. The charged particles are exposed to a first electric field extending between the source and the intermediate electrode prior to being exposed to a second electric field extending between the intermediate electrode and the second electrode. The magnitude of the first electric field is less than the peak magnitude of the second electric field, and may be less than or equal to a minimum magnitude of the second electric field occurring during a phase acceptance time period associated with a phase acceptance of the particle accelerator. The accelerated charged particles emerge from the second electrode as a non-diverging or reduced divergence particle beam.

Abstract: A high power RF device has an electron beam cavity, a modulator, and a circuit for feed-forward energy recovery from a multi-stage depressed collector to the modulator. The electron beam cavity include a cathode, an anode, and the multi-stage depressed collector, and the modulator is configured to provide pulses to the cathode. Voltages of the electrode stages of the multi-stage depressed collector are allowed to float as determined by fixed impedances seen by the electrode stages. The energy recovery circuit includes a storage capacitor that dynamically biases potentials of the electrode stages of the multi-stage depressed collector and provides recovered energy from the electrode stages of the multi-stage depressed collector to the modulator. The circuit may also include a step-down transformer, where the electrode stages of the multi-stage depressed collector are electrically connected to separate taps on the step-down transformer.

Abstract: An optical apparatus for ranging and communication in free space comprises a rangefinder comprising a device for transmitting an optical signal to a target and a device for receiving the signals backscattered by the target. A system for optical communication in free space comprises a device for transmitting an optical signal to a remote optical receiving device. The transmitting device of the rangefinder and transmitting device of the communication system is a transmitting device common to the rangefinder and communication system and transmitting pulses of peak power greater than 50 W and shape factor less than 0.01 or a modulated continuous signal of peak power less than 10 W and shape factor equal to approximately 0.5 and the apparatus comprises a supervisor controlling the common transmitting device according to two modes, the pulse mode to perform the ranging function, or the modulated continuous mode to perform the optical communication function.

Abstract: A stabilized high-voltage power supply is disclosed, having a general setup similar to a pulse-step modulator. The power supply comprises a plurality of DC power modules (40) having their outputs connected in a series configuration. Each power module comprises a DC voltage source (41), a DC-DC converter (42), and an output switching circuit (43). The total output voltage of the power supply is regulated by regulating the DC link voltage at the output of each power module. This is achieved by an appropriate feedback control circuit driving the DC-DC converter of each power module. In this manlier, low output ripple and a rapid response to changes in output current can be achieved. The power supply may be used, e.g., as the cathode power supply of a gyrotron.

Abstract: The invention relates to a method for generating light with a desired light color by using at least one light-emitting diode emitting red r-LED, at least one light-emitting diode emitting green g-LED, at least one light-emitting diode emitting blue b-LED and at least one light-emitting diode emitting white w-LED. In order to improve the CRI value, according to the invention it is proposed that weighting values ascertained according to the RGB algorithm and further weighting values ascertained according to the RGBW algorithm be combined together by using a correction factor.

Abstract: Electron sources for a cathodoluminescent lighting system are disclosed. An electron source is a broad-beam reflecting-type electron gun having a cathode for emitting electrons and a reflector and/or secondary emitter electrode and no grids. An alternative electron gun has a cathode having a heater welded to a disk, the disk having an emissive surface on a side facing a dome-shaped defocusing grid and an anode. A lighting system incorporating the electron sources has an envelope with a transparent face, an anode with a phosphor layer to emit light through the face and a conductor layer. The system also has a power supply for providing from five to thirty thousand volts of power to the light emitting device to draw electrons from cathode to anode and excite a cathodoluminescent phosphor, and the electrons transiting from cathode to anode are essentially unfocused. A power-factor-corrected embodiment is also disclosed.

Abstract: A device for lighting a room is described. The device has an envelope with a transparent face, the face having an interior surface coated with a cathodoluminescent screen and a thin, reflective, conductive, anode layer. There is a broad-beam electron gun mounted directly to feedthroughs in a base of the envelope with a heated, button-on-hairpin, cathode for emitting electrons in a broad beam towards the anode, and a power supply mounted on the feedthroughs at the base of the envelope that drives the cathode to a multi-kilovolt negative voltage. A two-prong snubber serves as an anode contact to permit the power supply to drive the anode to a voltage near ground. A method of manufacture of the anode uses a single step deposition and lacquering process followed by a metallization using a conical-spiral tungsten filament coated with aluminum by a thermal spray coating process.

Abstract: A stabilized high-voltage power supply is disclosed, having a general setup similar to a pulse-step modulator. The power supply comprises a plurality of DC power modules (40) having their outputs connected in a series configuration. Each power module comprises a DC voltage source (41), a DC-DC converter (42), and an output switching circuit (43). The total output voltage of the power supply is regulated by regulating the DC link voltage at the output of each power module. This is achieved by an appropriate feedback control circuit driving the DC-DC converter of each power module. In this manlier, low output ripple and a rapid response to changes in output current can be achieved. The power supply may be used, e.g., as the cathode power supply of a gyrotron.

Abstract: Electron sources for a cathodoluminescent lighting system are disclosed. An electron source is a broad-beam reflecting-type electron gun having a cathode for emitting electrons and a reflector and/or secondary emitter electrode and no grids. An alternative electron gun has a cathode having a heater welded to a disk, the disk having an emissive surface on a side facing a dome-shaped defocusing grid and an anode. A lighting system incorporating the electron sources has an envelope with a transparent face, an anode with a phosphor layer to emit light through the face and a conductor layer. The system also has a power supply for providing from five to thirty thousand volts of power to the light emitting device to draw electrons from cathode to anode and excite a cathodoluminescent phosphor, and the electrons transiting from cathode to anode are essentially unfocused. A power-factor-corrected embodiment is also disclosed.

Abstract: A voltage control apparatus used for an electron tube or a power supply apparatus includes a detecting circuit for detecting current flowing through a helix electrode, a voltage-limiting circuit for controlling a potential difference between the helix electrode and the anode electrode based on a predetermined voltage level; and a switch for switching based on an output from the detecting circuit. The switch connects the helix electrode and the anode electrode through the voltage-limiting circuit, or causes a short circuit between the helix electrode and the anode electrode.

Abstract: A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value.

Abstract: A light source includes a hot electron source comprising a cathode that generates an electron beam and an anode comprising a germanium containing material positioned adjacent to the cathode. The anode is biased so that the electron beam accelerates towards the anode where some electrons are absorbed and then relax to both direct energy bands and indirect energy bands causing stimulation of low energy electrons from the indirect energy band to the direct energy band, thereby creating electroluminescence.

Abstract: An apparatus that includes a traveling-wave tube having an electron gun having a cathode. The apparatus also includes a first power supply for establishing a first electric potential between the cathode and an anode and for providing an operational current to the cathode to generate a beam of electrons. The apparatus also includes a slow-wave structure having a passage through which the beam of electrons passes. The apparatus also includes a second power supply for providing a voltage to a beam focusing electrode to establish an electric potential between the cathode and the beam focusing electrode. The apparatus also includes a switching module coupled to the first power supply and the second power supply, the switching module providing a current path between the cathode and the beam focusing electrode, wherein the current path is disabled when a biasing current is below a predetermined level.

Abstract: A microwave generator (10) having a hollow central electrode (12) with a front face including hollow emmission element (18), and having an outer electrode (14), which coaxially surrounds the central electrode (12) along an axially extending resonator section (16). The two electrodes (12, 14) define a spark gap (36) and are connected to a high-voltage source (38). An ultracompact microwave generator (10) is implemented by the high-voltage source (38) being arranged in the hollow central electrode (12) of the microwave generator (10) rather than on the outside thereof.

Abstract: The invention relates to a microwave power tube consisting of an electron gun comprising a cathode that generates an electron beam in a microwave structure of the tube, and a collector for collecting electrons from the beam. In addition, the tube comprises a magnetic device for spreading the beam in the collector, which generates a periodic amplitude-modulated magnetic spread field Bblm. The invention is suitable for microwave power tubes.

Abstract: A system to regulate gyrotron power is configured to raise the filament voltage of a gyrotron to a standby voltage, then set the filament voltage to the normal standby voltage plus a current offset voltage before pulsing the gyrotron. The system is further configured to increase the filament voltage to a boost voltage that is higher than the standby voltage, thereby inducing a temperature increase in the cathode that offsets the cooling effect of radiating. The system is also configured to analyze a beam power of the gyrotron and adjust the filament voltage to bring a beam current within a range, and reduce the filament offset to zero such that the filament voltage is equal to the standby voltage.

Abstract: Discharge factors existing on a surface of an electrode or an insulator forming an electron gun are removed efficiently and effectively, thus simply and easily enhancing the withstand voltage property of the electron gun. A conditioning processing device of an electron gun is provided with a voltage supply section, a voltage adjusting section for adjusting the output voltage of the voltage supply section, and a current detection section for detecting a leakage current flowing between the electrodes of the electron gun. Further, there are attached a vacuum exhaust section for adjusting the inside of the electron gun in a reduced pressure condition and a pressure detection section.

Abstract: A voltage control apparatus used for an electron tube or a power supply apparatus includes a detecting circuit for detecting current flowing through a helix electrode, a voltage-limiting circuit for controlling a potential difference between the helix electrode and the anode electrode based on a predetermined voltage level; and a switch for switching based on an output from the detecting circuit. The switch connects the helix electrode and the anode electrode through the voltage-limiting circuit, or causes a short circuit between the helix electrode and the anode electrode.

Abstract: A multi-beam klystron apparatus is disclosed. A radio-frequency interaction unit pole piece is arranged between a main magnetic field generator and an output-side magnetic field generator. The magnetic circuit formed in the neighborhood of an output cavity of a radio-frequency interaction unit is separated from the magnetic circuit of the main magnetic field generator by the radio-frequency interaction unit pole piece. The output-side magnetic field generator increases the axial magnetic flux density in the neighborhood of the output cavity without curving the electron beams and thus prevents the spread of the electron beams in the neighborhood of the output cavity.

Abstract: A method and apparatus for accelerating charged particles are disclosed, wherein the method comprises using at least a transverse component of a temporally and spatially shaped electromagnetic field to accelerate one or more charged particles.

Abstract: A magnet configuration for a power microwave tube with a resonant cavity comprises a permanent magnet (110) with an axis-aligned through-bore (135) of sufficient size to contain the resonant cavity. The permanent magnet has an inner chamber (140) that is centered on the axis (130) with opposite magnet poles aligned along the axis. The magnet configuration further comprises an electromagnet coil (120) fitting in the chamber and encircling the axis such that the coil produces a magnetic field that reinforces the magnetic field from the permanent magnet. An optional protrusion (125) spanning the through-bore narrows an air gap between the poles. The method provides a magnetic field in a power microwave generator by combining a permanent magnet with an electromagnet in accordance with the magnet configuration and energizes the electromagnetic coil, which may be by pulsing the coil current.

Abstract: A conductive film isolated from an inner conductive film is formed on an inner wall of a neck. Assuming that, among a plurality of focusing electrodes constituting an electron gun, a position in a tube axis direction of an end on an anode side of an anode-side focusing electrode placed at a position closest to the anode side is P0; among electrodes supplied with substantially the same voltage as that of the anode-side focusing electrode and arranged continuously from the anode-side focusing electrode, a position in the tube axis direction of an end on a beam generating portion side of an electrode placed at a position closest to the beam generating portion side is P1; in the tube axis direction, a position of an end on the beam generating portion side of the conductive film is PL1 and a position of an end on the panel side of the conductive film is PL2, the position P0 is placed between the position PL1 and the position PL2.

Abstract: Disclosed are a cathode ray tube and a funnel therefore. An anode button is installed on the funnel to meet the condition of 2.8?T, in which T is a B/A ratio, A is a distance on a central axis of the funnel between a seal edge face of the funnel, which abuts a panel, and the anode button, and B is a distance on the central axis of the funnel between the anode button and a neck seal of the funnel, which is positioned at the opposite side of the seal edge face in the funnel. According to this invention, it is possible to prevent mechanical interference and electrical interference, such as distortion of deflection magnetic field, caused depending on the installation position of the anode button on the funnel.

Abstract: A method and circuit for generating independent top and bottom corner correction using a single fourth order function is described. The top and bottom corner correction signal may be included in an east-west corrected voltage to correct an asymmetry of a picture with respect to a horizontal axis and a vertical axis of the picture. Two switch signals based on a ramping voltage, which is used to sweep an electron beam, and two clock signals control a sample-and-hold circuit. The sample-and-hold circuit is arranged to sample a fourth order voltage during a top portion and a bottom portion of the ramping voltage and provide two independent correction voltages Vout—top and Vout—bottom. The correction voltages are then provided for top and bottom corner correction to the east-west corrected voltage.

Abstract: Based, in part, on an input video signal, an autobias circuit generates red, green, and blue channel video signals, which are received by external drivers to drive cathodes in a CRT. The autobias circuit also provides gain and bias control signals based on a sense current. The external drivers generate the sense current such that the sense current is proportional to the sum of the beam currents flowing from the cathodes. The sense current has an error caused by current flowing through external recharge resistors. A correction current (Ivideo) is subtracted from the sense current to compensate. The correction current is generated according to the equation Ivideo=(Vs/Rkin)*[(Vref/Rext)/(Vref/Rin)], where Vkin and Rin are matched internal monolithic resistors, Rext is the resistance of another external resistor that is matched to the external recharge resistors, and Vs is the sum of the red, green, and blue channel video signals.

Abstract: With respect to a highly flat glass bulb for cathode ray tube having an effective screen diameter along a diagonal axis of a glass panel 10 of more than or equal to 500 mm, and an average radius of curvature of an outer surface of a face portion of more than or equal to 10,000 mm, a ratio between a length h of a skirt portion 13 of the glass panel and a distance H in the tube axis direction from an edge surface portion where a funnel is sealed with the glass panel to a reference line is defined so as to fall within a predetermined range in relation to a deflection angle ? of the funnel representing substantial degree of divergence in the tube axis direction of the funnel, thereby achieving reduction of weight of the glass bulb while maintaining a certain mechanical strength, as well as suppressing breakage during frit seal heating process.

Abstract: A display apparatus has a cathode ray tube bulb which includes a panel displaying a picture thereon, a funnel combined with the panel, and a neck connected to the funnel. The display apparatus further comprises an electron gun unit which includes an electron gun main body inserted into the neck and a boss part protruding from the neck at a rear part of the electron gun main body and having a plurality of pins disposed therearound, and a video unit which includes a video PCB disposed parallel to the axis of the neck and a boss holder vertically provided on the video PCB and combined with the boss part so as to transmit a video signal from the video PCB to the electron gun unit. With this configuration, space for installation of the video PCB is minimized, and the video unit is not easily separated from an electron gun unit.

Abstract: Intensive microwave radiation in particular of great band width and energy over a relatively long period of time in the form of long pulse packets with a high pulse repetition frequency and a very high frequency spectrum can be achieved if microwave irradiation is effected during the discharge of a capacitive high-voltage generator (35) by way of the antenna (26) into a series of successive capacitors (13) to be connected in parallel. They are preferably constructed in the form of a concentric stack, connected to the antenna (26), of which the outer electrodes (16) which are at a reference potential are in the form of a continuous tube within which annular electrodes (15) are disposed on a carrier (20) in axially spaced relationship with each other in such a way that at the same time they act as the electrodes of arc switches (39) for successively switching on subsequent capacitors (13).

Abstract: A system for regulating beam current in a cathode ray tube. The system includes test signal timing and pulse generation logic for outputting test signals operable to stimulate a cathode ray tube at two voltage levels. The system further includes a circuit that inputs the test signal timing and determines correction signals based on signals derived from the cathode in response to stimulating the cathode ray tube at the two voltage levels. The correction signals may include a gain correction signal, a bias correction signal or both. The gain correction signal modifies a signal output to a gain driver that may be AC coupled to the cathode. The bias correction signal output to a clamping circuit coupled to the cathode.

Abstract: Expressing a perveance of an electron gun to be determined by a form of the electron gun as P&mgr;, a voltage to be impressed on an accelerating electrode Va and a beam current Ib, voltage Va which satisfies the following expression, Ib<P&mgr;×Va3/2 is impressed on the accelerating electrode. Further, the electric potential of the accelerating electrode is maintained at the highest level of all electrodes in the electron tube at all times.

Abstract: A video imaging apparatus comprises first and second cathode-ray tubes, each having an ultor electrode and a focus electrode. A power supply generates an ultor voltage, which may have a fluctuating voltage component produced by beam current variations, and which is coupled to first and second ultor electrodes of the first and second cathode-ray tubes. A high voltage amplifier generates a dynamic focus voltage component at a frequency related to a deflection frequency. A combining network combines the fluctuating voltage component and the dynamic focus voltage component to develop a combined, dynamic focus voltage. The combined, dynamic focus voltage is coupled to each of the first and second focus electrodes for developing from the combined, dynamic focus voltage each of a first dynamic focus voltage at the first focus electrode and a second dynamic focus voltage at the second focus electrode.

Abstract: An electron gun, having an electron source, a Wehnelt electrode, and acceleration electrodes, includes a control device for changing a field distribution formed by a first acceleration electrode of the acceleration electrodes to control characteristics of a final cross-over formed, by electrons from a first cross-over, at the final stage of the electric gun. The first cross-over is performed when the electrons emitted from the electron source are focused by the field distribution formed by the electron source, the Wehnelt electrode, and a second acceleration electrode of the acceleration electrodes.

Abstract: A main lens of an electron gun assembly comprises a sixth grid, a seventh grid, an eighth grid, and a ninth grid. An asymmetric lens section is created between a fifth grid and the sixth grid on a cathode side of the main lens. The asymmetric lens section has such asymmetry that lens functions of the asymmetric lens section acting on the electron beams are different between the horizontal direction and the vertical direction, and has a lens power varying in synchronism with the deflection of the electron beams. In this asymmetric lens, the asymmetry for a center beam differs from that for side beams.

Abstract: With respect to a highly flat glass bulb for cathode ray tube having an effective screen diameter along a diagonal axis of a glass panel 10 of more than or equal to 500 mm, and an average radius of curvature of an outer surface of a face portion of more than or equal to 10,000 mm, a ratio between a length h of a skirt portion 13 of the glass panel and a distance H in the tube axis direction from an edge surface portion where a funnel is sealed with the glass panel to a reference line is defined so as to fall within a predetermined range in,relation to a deflection angle &thgr; of the funnel representing substantial degree of divergence in the tube axis direction of the funnel, thereby achieving reduction of weight of the glass bulb while maintaining a certain mechanical strength, as well as suppressing breakage during frit seal heating process.

Abstract: A cold cathode-ray tube driving method by using a voltage with fixed phase shift to drive each cold cathode-ray tube of a backlighting module in a large size LCD; a circuit with phase excursion formed by the voltage so to provide a fixed phase shift between abutted loads to supply a highly consistent power source and to effectively control electricity leakage due to unstable phase shift between abutted loads.

Abstract: There is provided a cathode ray tube capable of displaying high quality images by suppressing eddy current from occurring and by realizing the velocity modulation. A cylindrical focusing electrode is divided into first cylindrical focusing electrode 4B and second cylindrical focusing electrode 4T and the gap between the both electrodes formed and divided by optimizing the length of the second cylindrical focusing electrode 4T in the tube axial direction is enlarged substantially to increase the infiltration of the velocity modulating magnetic field to the non-electric space of the focusing electrode 4. An electrode 4a having the equal potential with the focusing electrode 4 is disposed at the gap to suppress eddy current from being generated.

Abstract: A cathode ray tube has a three-gun type electron gun. The electron gun includes a cathode, a G1 electrode, a G2 electrode aligned in line in this order, the G1 electrode and the G2 electrode having beam-passing holes formed therein. A supporting member supports the cathode in position. A GM electrode is added between the G1 and G2 electrodes and has a beam-passing hole smaller than the holes formed in the G1 electrode and the G2 electrode. The supporting member and the G1 electrode are formed with measurement holes. The G2 electrode may also be formed with a measurement hole therein. A measurement element is inserted through the measurement holes to measure a distance between the G1 electrode and the G2 electrode, and a distance between the GM electrode and the G2 electrode.

Abstract: Disclosed is a structure of a an electron gun for a color cathode ray tube capable of reducing a drive voltage by creating an optimum relation among a cathode, a first electrode, and a second electrode mounted in the electron gun, and preventing degradation in responsiveness to input signals on a high-resolution screen and a focus characteristic.

Abstract: A CRT device with an electron gun provided therein includes control means for controlling voltages applied to a cathode and a control electrode constituting the electron gun. The control means exerts control on each electrode voltage so that the difference between the cutoff voltage of the cathode and the voltage of the control electrode is greater when the luminance level of a luminance signal separated from picture signal is higher, thereby minimizing a spot diameter.