Abstract: In a flat cathode ray tube display apparatus a low energy, electron beam (18) is directed substantially parallel to a faceplate (12) carrying a phosphor screen (14) in a space between a deflection electrode array (22) and the input side of an electron multiplier (16) adjacent the screen where it is deflected by operation of the electrode array (22) in field scann manner towards the screen to provide a raster scanning input to the multiplier. the deflector electrodes (23) of the array are switched successively between two voltage levels in each field to step the line scanning beam with the switching voltages in successive fields differing whereby two interleaved sets of display lines are drawn in two consecutive fields which together constitute a display frame having the required number of active display lines. The voltage switching circuit (52) may be carried on a substrate adjacent the electrode array.

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

Abstract: A flat display tube comprising an emission system (3) for emitting a planar electron beam (20), a modulation system (22) and a deflection system (5a, 5b, 28) for deflecting the planar electron beam towards the modulation system (22), which flat display tube also comprises a selection system (23) for selecting the planar electron beam transversely to this beam. The thickness of the electron beam (20) is increased by mutual repulsion of the electrons in the planar electron beam. The selection system in the flat display tube precludes that this adversely affects the resolution of the picture on the display screen.

Abstract: The invention relates to a flat display device with a faceplate (1) having either an outward curvature or bulging inwards under the action of atmospheric pressure, the device also comprising a planar deflection device (8) to deflect the electron beams (13, 14) in each line. With a view to obtaining a pure-color image, the deflection voltages are corrected according to the particular distance between the deflection device (8) and the faceplate (1), thereby ensuring that the electron beams (13, 14) will impinge only on the appropriate equidistant phosphor dots or strips (4). The formula for calculating the correction factor (K) is stated.

Abstract: A monotube CRT includes an envelope which comprises a first section that houses the electron gun and a second section that houses a fiber optics faceplate along a sidewall. An array of electromagnets is disposed along the second section for deflecting the electron beam from its longitudinal path through the envelope transversely to trace a linear scan on the faceplate. The first section of the envelope is a circular cylinder whose axis is coaxial with the longitudinal path of the electron flow. The second section of the envelope is essentially rectangular or elliptical in cross section and the undeflected beam flows adjacent one narrow sidewall opposite the sidewall housing the faceplate. Each electromagnet of the array includes a core portion adjacent said one narrow sidewall and pole pieces that flank the wide sidewalls of the section.

Abstract: In a flat, vacuum-enclosed picture-reproducing device having a phosphor-coated glass faceplate and a shallow tray-shaped rear housing in which a cathode consisting of a periodic array of oxide-coated heating wires is located in front of a counterelectrode, and which contains a control arrangement between the cathode and the faceplate, a perforated anode is present between the heating wires and the control arrangement, which consists of two layers of electrodes, and the counterelectrode has segments arranged perpendicular to the longitudinal dimension of the oxide-coated heating wires.

Abstract: A flat television screen, comprising several electron-emitting devices, each essentially consisting of an electric power supply connected to two plates of a capacitor supplying by one of these plates at least one field emission and an extraction grid placed close to the top of the field emission, the grid itself being connected to the other plate of the capacitor by a variable voltage generating device, these devices being connected together facing a fluorescent screen placed to receive a flow of electrons emitted by the field emission of each of the devices.

Abstract: In order to prevent the walls of the envelope (10) of a flat panel display tube having a large area screen from imploding, supporting walls (22) are provided to divide the interior of the envelope into a plurality of modules. Each module has its own electron beam generating means (24) for producing a low voltage, low current, intensity modulated electron beam (26) which is directed vertically upwards. A laminated channel plate electron multiplier (28) is disposed across the module and extends substantially parallel to the front and rear walls (12, 14) of the envelope. A single column of channels in the electron multiplier (28) is illustrated. The spacing of the channels determines the vertical resolution of the image produced. In order to deflect the electron beam (26) into a particular channel, a plurality of deflector electrodes (30) are disposed on the rear wall (14).

Abstract: In a flat cathode ray tube display apparatus a line scanning, low energy, electron beam (18) is directed substantially parallel to a faceplate (12) carrying a phosphor screen (14) in a space between a deflection electrode array (22) and an input side of an electron multiplier (16) adjacent the screen where it is deflected by the electrode array (22) in field scan manner towards the screen. The deflector electrodes (23) in the array correspond in number to the conventional raster lines to be displayed and are switched successively between two voltage levels to step the line scanning beam. The electrodes' voltage switching drive circuit (52) may be carried on a substrate adjacent the electrodes thereby reducing the number of leadthroughs in the tube's envelope (15). For color display the screen comprises a pattern of different color phosphor elements and a color selection electrode arrangement (38) is situated at the output side of the multiplier (16).

Abstract: A color display system including a cathode ray display tube (10) of the kind which has an electron multiplier (16) arranged adjacent a luminescent screen (14) comprising a repeating pattern of three different color phosphor elements and pairs of color selection electrodes (38, 40) associated with each channel of the multiplier operable to control the direction of the electron beam from the channels for color selection purposes uses a switching bridge circuit comprising semiconductor switching device (52, 54, 56, 58), e.g. MOSFETs, connected between voltage supplies for switching the voltage applied to each one of the pair of electrodes between three respective levels in synchronism to achieve a predetermined color selection sequence. The semiconductor devices are controlled by synchronized waveforms from a pulse generating circuit (86) via optocouplers (88) enabling the switching bridge circuit to be floated at a high potential.

Abstract: During a period in which electron beam emission to a photo-emissive screen is inhibited, a heating current is supplied to a cathode. During a period in which electron beam emission to the screen is enabled, the supply of the heating current to the cathode is interrupted and the potential at the cathode is varied with a video signal. During the beam emission enabling period, the interruption of the heating current supply allows the electron beam to be uniform along the cathode, since the heating current would cause a potential gradient or variation along the cathode. In addition, during the beam emission enabling period, since the cathode potential is varied with the video signal, the electron beam is modulated in accordance with the video signal.

Abstract: In a flat type cathode ray tube having one or plural parallel (vertical) line cathodes (10) and a plurality of scanning electrodes (12) consisting of insulated parallel (horizontal) metal strips, which are to be impressed with respective scanning pulses (FIG. 6, FIG. 21) to make vertical scanning of electron beams from the line cathodes: undesirable vibrations of the line cathode (10) are suppressed by touching wire-shaped dampers (28, 38A, 38B, 48, 64, 65) on the line cathode (10), and by selecting the frequency of the scanning pulses higher than natural vibration frequency of the line cathode (10).

Abstract: A cathode-ray tube having an electron gun for emitting an electron beam and a reflecting electrode for forming in front thereof a substantially planar reflecting potential surface which reflects the electron beam from the electron gun toward an anode target formed on the inner surface of the tube.

Abstract: An electron gun of a flat plate type image display apparatus for use in a field of an image information apparatus is described. A rear electrode part of the electron guns is formed by a flat plate type rear electrode which has a conductive film on its surface, and is arranged with a constant distance from the plural line electrodes. Plural spacers are disposed between the plural line electrodes (2), with one end of each fixed on the rear electrode and conductive films formed on the surfaces. The fabrication of the electron gun is simplified and furthermore, electric field is stabilized by prevention of generation of electric charge and generation of unevenness of luminance on a surface of an anode.

Abstract: A CRT display system providing a raster pattern, possibly for a flat screen CRT, has an oscillator driving a Line counter. The Line counter drives a Field counter and a Line DAC. The Field counter drives a Field DAC. In response, there are generated signals, representing functions, to be applied to the CRT deflection plates, and whereby there is represented the inverse of any function representing distortion of the raster pattern required to be corrected. At least one further DAC may be provided, comprising one of a pair of interacting DAC's, with one DAC driven by the Line counter, and one DAC driven by the Field counter, the output of said further DAC causing a combined function to be represented by the output of said other DAC. Said other DAC may comprise either the Line DAC, or the Field DAC; or said further DAC of another pair of interacting DAC's.

Abstract: A charged-particle beam electric field deflector includes plural (n) pairs or sets of facing deflection electrodes to accelerate and deflect the beam. Different d.c. acceleration voltages are superimposed on a common deflection voltage and applied to the electrode pairs so that electrode pair k is responsive to acceleration voltage k and the common voltage, where k is selectively each of 1 . . . n. The distance between each pair of facing electrodes is constant or increases along the beam path, while the length of each of the deflection electrodes has a given relationship as a function of the distance between the facing electrodes of each pair. The deflector is used in a flat CRT.

Abstract: A flat panel display device is divided into channels and includes deflection electrodes for scanning electron beams horizontally across the channels. Convergence electrodes are voltage biased to converge the electron beams at points along the transverse line scanned by the electron beams. A compensation voltage generator provides compensation voltages to compensate for horizontal landing errors of the electron beams.

Abstract: An electron beam detecting electrode is provided laterally outside an effective picture area, to detect a beam current amount and vertical position of the electron beam. An amount of the electron beam current and a position of the electron are controlled by utilizing an output signal of the electron beam detecting electrode, and a uniform brightness and a uniform distance between horizontal scanning lines are obtainable.

Abstract: A flat display tube comprising an envelope including a faceplate on which a luminescent screen is provided. An internal divider divides the interior of the envelope vertically into a front portion adjoining the faceplate and a rear portion which communicates with the front portion via a space between the upper edge of the divider and a peripheral wall of the envelope. An upwardly directed electron gun and line scanning means are disposed in the rear portion. The line deflected electron beam is directed to a 180.degree. reversing lens which deflects the electron beam into the front portion. An electron multiplier is disposed in the front portion adjacent to, but spaced from, the faceplate. The electron beam in the front portion undergoes frame deflection by means of a plurality of selectively energized, vertically spaced, horizontally elongate electrodes. The pattern of energization of the electrodes is such as to deflect an end portion of the electron beam to the input side of the electron multiplier.

Abstract: A flat type cathode ray tube comprises, in a vacuum enclosure, a plurality of vertically extending line cathodes, as many vertical scan electrodes as 1/n (n.gtoreq.2) of the number of horizontal scan lines arranged behind the line cathodes perpendicularly to the line cathodes, and modulation electrodes, planar grid electrodes, vertical deflection electrodes, horizontal deflection electrodes and a phosphor screen all of which are arranged sequentially in front of the line cathodes. The modulation electrodes are separated into a plurality of planar sections which are arranged in one-to-one correspondence with the respective line cathodes. The vertical deflection electrodes include two planar electrodes having respective electron beam passing openings provided therein which are shifted from each other. The horizontal deflection electrodes are divided into a plurality of sections in the direction of the electron beam paths.

Abstract: A fluorescent display device is disclosed which is capable of improving visibility of luminous display of anodes. In the device, cathodes are arranged laterally out of an area opposite to the anodes so as not to hinder the observation of the luminous display. The device also includes a deflecting electrode for deflecting and diffusing electrons emitted from the cathodes so as to direct them toward the anodes.

Abstract: A channel plate electron multiplier is mounted parallel to, but spaced from, the screen. The electron multiplier comprises a stack of juxtaposed substantially planar apertured dynodes with the apertures therein aligned to form channels. An apertured extractor electrode is mounted on the output side of the electron multiplier. Preferably two or more foraminous deflector electrodes are mounted on the extractor electrode. The apertures in the foraminous deflector electrodes have the same pitch as the channels of the electron multiplier but are offset laterally relative to each other and to the axes of the channels by amounts which allow the emergent electron beam from each channel to pass through to the screen without impinging upon the deflector electrodes. By applying a potential difference between the deflector electrodes an electron beam emerging from its respective channel is deflected laterally onto a respective one of its associated group of phosphor stripes.

Abstract: A flat visual display device is disclosed herein and includes a flat face plate having a front face and an opposite back face and electrically positive means on the latter which, as a result of the impingement of the electrons thereon, provides a visual image through the front face of the face plate. The device utilizes an arrangement including cathode means for establishing a uniformly dense space-charge cloud of free electrons within a planar band parallel with and rearward of the back face of the display face plate. Means including an apertured address plate disposed in spaced-apart confronting relationship with the back face of the face plate between the latter and the uniform space-charge cloud acts on the electrons within the cloud in a controlled way so as to cause the electrons acted upon to impinge on specific areas of the electrically positive back face plate means of the display face plate in order to produce a desired image through the face plate's front face.

Abstract: A video image display apparatus comprising line cathodes for emitting electron beams, a phosphor screen having a phosphor layer which emits light at impingement by said electron beams, and a vacuum enclosure containing the above-mentioned components therein, wherein undesirable vibration is prevented by providing damping strings across and lightly touching the line cathodes for reducing the vibration of the line cathodes by their damping effect.

Abstract: A flat matrix cathode-ray tube (CRT) in which the brightness of a display picture can be readily adjusted according to environmental brightness. In the flat matrix CRT, the grid electrodes are made up of the scanning electrodes and the data electrodes which form the matrix structure with the scanning electrodes, and the pulse voltage for gradations required are applied selectively to the scanning electrodes and the data electrodes so that the picture elements determined by the scanning electrodes and the data electrodes to which the pulse voltage are selectively applied are caused to emit light. Slots the number of which is determined in correspondence to the number of gradations selected, are provided either in the waveforms of the voltages applied to the scanning electrodes or in the waveforms of the voltages applied to the data electrodes in such a manner that the slots occur at regular intervals.

Abstract: In a flat image display tube, a phosphor screen having an image display region and index region, a plurality of electron beam generators and a plurality of horizontal deflection electrodes are provided. The image display region has three primary color phosphor stripes and each is sequentially arranged alternately with black stripes in a horizontal direction. The index region is arranged adjacent to the image display region and has index phosphor stripes arranged in a predetermined relationship to the three primary color phosphor stripes.

Abstract: A display tube of the kind in which a line-scanned, low-energy electron beam (32) is directed into a space between a planar array of elongate deflection electrodes (42) and the input side of a laminated dynode channel electron multiplier (44). The deflection electrodes are switched sequentially by driving means between two potential levels (V.sub.1, V.sub.2) so as to deflect and scan the incoming beam frame-wise over the multiplier input, the current-multiplied beam emanating from the multiplier being directed onto a screen (16) to produce a display. By ensuring that the beam acceleration voltage, Va, satisfies the relationship 1.3 Vs<Va<2 Vs, where Vs=V.sub.2 -V.sub.1, beam spot size at the multiplier input is maintained and Moiree patterning effects in the display are effectively suppressed. The multiplier input electrode and final anode of the electron gun are advantageously held at the higher (V.sub.2) of the switched potentials.

Abstract: A method of producing uniformity of emission a characteristics of a plurality of electron beam sources in a cathode ray tube, by deriving and storing data values for producing respective correction voltages to be applied to modify the emission characteristics. Each data value is obtained by sensing a current which flows through one of the control electrodes when a high voltage electrode is set to a relatively low potential, comparing this current with a reference value and storing the difference for use in subsequently producing a correction voltage. Data values are derived during successive time intervals, with corresponding correction voltages being successively applied to achieve feedback operation, for greater correction accuracy.

Abstract: A CRT display system providing a raster pattern has digital means 30, 31, 32 to drive a DAC 34. In response, there are supplied analogue signals, on a line 37. There are also provided pulse generating means 90 controlled by the digital means, and integrating means comprising two integrators. Each integrator is connected individually to an X deflection plate 14 of the CRT, and comprises an amplifier and a feedback capacitor. One capacitor C2 is charged by negative-going pulses, and the other capacitor C2' is charged by positive-going pulses, until the pulses are removed, when the required ramps are applied to the deflection plates. Then a current flows through a transistor T7, and is controlled by the DAC output on the line 37. Hence, the waveforms applied to the deflection plates cause distortion of the raster pattern otherwise obtained, to be corrected, the DAC output representing a function comprising the inverse of the function representing the distortion.

Abstract: An electronic flash includes a main capacitor having a discharge loop in which a circuit arrangement including a flash discharge tube, a switching element and an emission controlling capacitor is connected. During the time the flash discharge tube is maintained excited, the emission controlling capacitor is either charged or discharged to cause an emission of flashlight from the flash discharge tube.

Abstract: A flat picture reproducing device includes a vaccum-tight envelope containing an electrode matrix formed of row conductors and column conductors disposed in front of the row conductors and having holes at respective crossings thereof, the matrix dividing the interior of the envelope into a rear and a forward chamber; an areal electron source in the rear chamber; elongated vertical deflection electrodes disposed in the forward chamber in a plane parallel to the plane of the matrix and, respectively, running between rows of the holes parallel to the row conductors, a respective single one of the vertical deflection electrodes being disposed between respective hole rows of adjacent pairs of the hole rows; the envelope having a wall on the forward side thereof coated with a layer of material luminescent when excited by electrons; an addressing circuit for scanning the row conductors sequentially to construct a picture line-by-line, each of the row conductors remaining addressed for at least one picture-row period

Abstract: An electron injection structure for the beam guide meshes of a flat panel display has apertures with different dimensions to optimize beam focusing for different purposes. The first period of apertures has strong focusing normal to the plan of the guide meshes. A plurality of periods have strong focusing in a direction parallel to the lateral dimension of the guide meshes. Another plurality of apertures matches the beams to the propagation section of the beam guide.

Abstract: A deflection circuit having particular application to a flat cathode ray display tube in which a channel plate electron multiplier is disposed parallel to, and spaced from, a cathodoluminescent screen and a low current, low voltage electron beam is scanned over the input side of the electron multiplier by means of a variable electrostatic field created between a planar array of substantially parallel elongate electrodes and the input side of the electron multiplier. In order to generate the variable electrostatic field a deflection circuit is provided having a plurality of ramp voltages generating stages, each stage being connected to a respective elongate electrode. The deflection circuit is operated in such a manner that the completion of the generation of a ramp voltage in one stage is used to trigger the next required stage.

Abstract: The disclosure relates to an apparatus and method for forming a scanning electron beam for use in a flat screen cathode ray tube device. An analog addressing method enables scanning of one axis of the screen of the CRT device. During scanning, all portions of a sheet of electrons emitted by a line cathode are deflected at any given time and blocked by an analog horizontal-positioning deflection grid except for one narrow portion disposed along the length of the line cathode. At the one portion, a narrow beam of electrons is formed. The grid contains an address plate and a load plate. The load plate creates a voltage gradient causing each location along its horizontal axis to be at a distinct voltage. Horizontal scanning is accomplished by applying a varying central voltage to the address plate. This varying voltage will be matched by an equal voltage at a single predetermined location along the horizontal axis of the load plate adjacent to which electrons can pass undeflected in the form of a beam.

Abstract: Apparatus and method for substantially equalizing the potential drop along a line cathode used in an electron beam source adapted for use in a flat display device. The apparatus and method ensure that electrons from a power source are fed through both ends of the line cathode, substantially simultaneously. Thereby, the potential drop along the axial length of the line cathode is decreased, improving the uniformity of brightness of the display.

Abstract: A flat cathode-ray tube wherein a horizontally uniform sheet-like electron beam is vertically deflected and modulated with a video signal, with the modulated electron beam irradiating a portion of a phosphor screen, includes a modulation electrode assembly arranged by n electrode groups, each consisting of at least one first electrode group and at least one second electrode group, the first electrode group having vertically elongated stripe electrodes, each having one or n (n is an integer of 2 or more) openings or slits corresponding to each pel and which are aligned in the horizontal direction on at least one plane such that all openings are equidistantly formed, the second electrode group having the same construction as the first electrode group or being arranged such that vertically elongated stripe electrodes, each having n openings or slits corresponding to n pels along the horizontal direction are aligned on at least one plane to equidistantly form the openings along the horizontal direction, all the o

Abstract: In a flat type cathode ray tube having a small depth relative to an image screen size, electron beams which are generated by heating vertically extending linear thermal cathodes are sequentially and vertically switched by a plurality of vertical scanning electrodes extending vertically and arranged perpendicularly to the linear thermal cathodes, are transmitted through an electron beam generating electrode having apertures formed therein corresponding to the linear thermal cathodes. The electron beams are horizontally deflected by horizontal deflection electrodes, and then directed to a phosphor layer on an image area of a faceplate. The electron beams are modulated by applying a modulation pulse voltage together with a heating D.C. voltage to the linear thermal cathodes, or by applying a modulation pulse signal to a modulation electrode arranged close to the electron beam generating electrode.

Abstract: A compact color display tube is provided in which a modulated electron beam enters a repelling trajectory control field, formed between a mesh electrode and a planar electrode, at an acute angle .alpha.. The beam follows a parabolic trajectory and approaches a target electrode bearing bands of phosphor stripes at substantially the same angle. The mesh electrode, comprising a plurality of parallel conductors, is disposed adjacent to the target electrode. The conductors of the mesh electrode extend parallel to the stripes and are spaced at a pitch corresponding to the pitch of the repeating bands of phosphor stripes. The target electrode is held at a potential such that the electron beam passing through the space between a pair of the conductors is focused and deflected onto a phosphor line of the target. A colored picture can be produced using a single electron beam by a spot wobbling technique or by scanning each phosphor line sequentially.

Abstract: A display tube having an electron gun and an electron beam deflector including first and second electrode arrangements disposed successively along the electron beam path from the electron gun. Each electrode arrangement includes a pair of resistive plates extending transverse to the path of the electron beam and disposed on opposite sides of the path. The plates of each electrode arrangement are joined at their top and bottom ends and a potential difference is applied across the plates to provide electrical fields substantially normal to the electron beam path. The fields provided by the respective electrode arrangements are equal and opposite so that the angular deflection of the electron beam caused by the first electrode arrangement is cancelled by the second electrode arrangement and the electron beam leaves the electron beam deflector on a path parallel to (or coincident with) the path it entered the deflector.

Abstract: A circuit for converting a TV receiver to operate in accordance with the system associated with received signals, there being either F or F' scan lines in a field, with F<F', includes a counter driven by pulses each representative of one end of a raster scan line, and having M stages, with F and F'<M<2F and 2F'. There is also means to preload the counter selectively with a count of R or R', where (M-2R)=F and (M-2R')=F'. Wide window means detects when a field sync pulse is within a window including the (M-R)th and (M-R') stages, and, in response, the counter, initially, is preloaded with R'. Decision logic means then detects whether a field sync pulse occurs after the Kth stage, with K=M-[R+R']/2, when R' is continued to be preload; or occurs before the Kth stage, when R subsequently is preloaded; and the required TV receiver conversion is completed.

Abstract: A picture image display apparatus has a flat type vacuum enclosure having a transparent face panel. A row of parallelly disposed linear thermionic cathodes are provided with an electron beam extractor electrode which produces a predetermined number of two dimensionally disposed electron beams out of the electron emission from the linear thermionic cathodes. A row of control electrodes is disposed parallelly in a direction perpendicular to those of the linear thermionic cathodes. A row of vertical deflection electrodes and a row of horizontal deflection electrodes are provided. A phosphor screen formed on the inner force of the face panel has an anode of thin metal film formed on its surface. A horizontal deflection signal generator issues a horizontal deflection signal having, in 1 cycle, a first scanning period wherein voltage increases and a second scanning period of the same length wherein voltage decreases.

Abstract: The video image display apparatus of flat tube type comprisinga phosphor screen, an electron beam source having a predetermined number (15) of line cathodes for in turn emitting said predetermined number of horizontal rows of electron beams, each row having a second predetermined number (320) of rod shaped electron beams,horizontal deflection means for horizontally deflection of the electron beams,vertical deflection means for vertical deflections of the electron beams of the horizontal rows,switch pair means of said predetermined number, each switch pair means comprises each-other oppositely working first switching means and second switching means, in each switch pair means the first switching means switches cathode heating current and the second switching means switches cathode bias voltage to bias a selected cathode in turn to enable electron emission, the switch pair means being controlled by switch control signal in turn impressed thereto.

Abstract: Flat picture reproduction device for displaying color pictures based upon three basic colors, containing a vacuum-tight envelope with an electrode matrix formed of row conductors and column conductors arranged in front of the row conductors. It has cutouts at the intersections of the row and column conductors and divides the interior of the envelope into a rear and a front chamber. A planar electron source is located in the rear chamber, elongated deflection electrodes located in the front chamber, between adjacent column conductors. The odd-numbered deflection electrodes are connected to a first voltage source, and the even-numbered ones to a second voltage source. Strip-shaped layers of luminescent phosphor is applied to the front side of the envelope wall adjacent one another in a periodic color sequence parallel to the column conductors.

Abstract: A display apparatus including a modular type display tube having a cathodoluminescent screen, elongate thermionic or P-N electron emitters, a channel plate electron multiplier and an apertured control plate between the emitters and the multiplier. The control plate has a plurality of switching electrodes on the side facing the emitter and a set of brightness electrodes on the opposite side and extending transversely to the switching electrodes. In order to compensate for variations in emission from the emitters, the brightness voltage to the brightness electrodes is turned-off and emission variations are measured by scanning using the switching electrodes. Correction voltages are computed and applied together with the modulation signal in synchronism with the scanning of the switching electrodes. An apertured shielding plate is provided to prevent the switching voltages at the switching electrodes from affecting the emissions from the emitters.

Abstract: A flat CRT type image display apparatus comprises a number of horizontally disposed parallel line cathodes and vertical and horizontal deflection means, and electron beams control means, and the deflection means includes digital memory means storing data for deflection signals, address counter means for producing address signal to read out the digital memory means, D/A converters for converting read out data to produce deflection signals and also a microcomputer for setting and adjusting data in the digital memory means.

Abstract: An electron beam injection structure for flat panel display device includes electron injection electrodes which span a beam guide assembly for propagating electron beams. One end of the electron injection electrodes is in closer proximity to the cathode than the corresponding end of the beam guide structure. The injection of electrons from the cathode to the beam guide structure therefore can be maximized by increasing the voltage on the electron injection electrodes while permitting changes in the operating voltages applied to the beam guide structure and other elements of the display device.

Abstract: A system for sequentially refreshing segments of the stored voltage characteristics of electron guns includes a clock gate. The clock gate passes clock pulses to a counter which refreshes the stored voltage signals. After a predetermined number of counts, the counter inhibits the clock gate until a vertical blank pulse enables the clock gate and the counter resumes counting.

Abstract: Apparatus for compensating for keystone distortion in a flat cathode ray tube in a relatively straightforward and inexpensive manner, and for providing a tube having relatively high resolution and reduced deflection aberration. A magnetic deflection yoke is utilized to scan the raster on the screen, and corrective deflective forces are provided on the electron beam to compensate for keystone. In a first embodiment, the corrective forces are provided by a magnetic hexapole field, in second and third embodiments by magnetic quadrapole fields in series with horizontal and vertical deflections respectively, and in a fourth embodiment by providing the combination of a hexapole field and orthogonal quadrapole field in series with horizontal and vertical deflections respectively.

Abstract: An electron beam guide assembly for a flat panel display device includes an acceleration electrode having two portions separated by a longitudinal slit. The display device also includes electrodes on support walls which divide the device into channels. By properly voltage biasing the acceleration electrode portions and the support wall electrodes, an electron beam is simultaneously directed to a particular color producing material and transversely scanned across the channels. A color display, therefore, can be produced using one electron beam per channel.

Abstract: A picture display device comprising an electron source for producing band-shaped electron beams, electron beam control means for controlling the selective passage of the electron beams, deflection means for horizontally and vertically deflecting the electron beams and display means for emitting light in response to impingement of the electron beams thereon. The electron source comprises a plurality of linear thermionic cathodes, a focusing electrode for focusing the electron beams emitted from each linear thermionic cathode to band-shaped electron beams and an electron beam emitting electrode having a plurality of apertures therethrough, and a negative pulse voltage is sequentially applied to the linear thermionic cathodes to emit the required electron beams for one scanning line.