Abstract: Disclosed is a flat panel display device for preventing a grid electrode from causing alignment error and being distorted due to thermal expansion and contraction. The grid electrode includes a mask portion with apertures through which electrons may pass, and fixtures arranged external to the mask portion with a predetermined margin for allowing thermal expansion and contraction of the mask portion. The fixtures are arranged symmetrical to each other up and down as well as left and right. The fixtures fix the mask portion such that the expansion and the extraction of the mask portion proceed opposite to one another.

Abstract: This invention provides a process for improving the field emission of an electron field emitter comprised of an acicular emitting substance such as acicular carbon, an acicular semiconductor, an acicular metal or a mixture thereof, comprising applying a force to the surface of the electron field emitter wherein the force results in the removal of a portion of the electron field emitter thereby forming a new surface of the electron field emitter.

Abstract: To provide an electron-emitting device, an electron source, an image-forming apparatus, and a method for manufacturing the electron-emitting device whereby it is possible to reduce a device capacity and a driving voltage, to improve the efficiency of emitting electrons, and to obtain high-resolution beam. The extracting electrode and the cathode electrode are provided on an insulating substrate, a layer having growth selectivity of fibrous carbon is formed on the cathode electrode, and the fibrous carbon is grown via catalyst particles formed on the layer.

Abstract: An object of the present invention is to enhance a converging property of an electron beam in an electron-emitting device in which a cathode electrode, an insulating layer, and a gate electrode are laminated and a through hole is formed by partially removing the gate electrode so as to obtain an exposed portion of the cathode electrode. In such an,electron-emitting device in which the cathode electrode, the insulating layer, and the gate electrode are laminated and the through hole is formed by partially removing the gate electrode so as to obtain the exposed portion of the cathode electrode, only a central region of the electron-emitting layer on the cathode electrode is connected to the cathode electrode. With this structure, it becomes possible to generate an electron beam only from the central region of the electron-emitting layer connected to the cathode electrode and to realize an electron-emitting device having a small beam diameter and a high-definition image-forming apparatus.

Abstract: An electron emission device where the electron emission of the emitter at the respective pixels is uniformly controlled. The electron emission device includes first and second substrates facing each other with a distance, and gate and cathode electrodes formed on the first substrate while interposing an insulating layer. Electron emission sources are electrically connected to the respective cathode electrodes. A resistance layer is disposed between the cathode electrode and the electron emission source in substantially the same plane as the cathode electrode. At least one anode electrode is formed on the second substrate. A phosphor screen is placed on a surface of the anode electrode.

Abstract: In a converging-type electron-emission source of a field-emission display, a substrate is provided and a silver paste is used to form a first electrode layer on the substrate by the process such as thick-film photolithography or screen-printing. A carbon nanotube is formed on the first electrode layer by thick-film photolithography or screen-printing, and a second electrode is formed on the carbon nanotube. A third electrode layer is formed on the first electrode layer around the second electrode layer by thick-film photolithography or screen-printing. The third electrode layer is higher than the second electrode layer, such that a converging exit is formed around the second electrode layer. A sintering step is performed. When the electron beam is generated, the electron beam is concentrated at the center of the converging exit to impinge a phosphor layer of an anode without causing gamut.

Abstract: An apparatus is provided for reducing color bleed in a flat panel display. The apparatus comprises an anode (30) with a plurality of phosphors (28) of at least two colors sequentially disposed thereon. A cathode (14) is arranged in parallel opposed position to and separated from the anode (30) and contains a plurality of pads (40) of emitters. Each pad (40) is disposed on the cathode (14) in spaced relationship to and aligned with one of the at least two colors, respectively, wherein electrons from each of the plurality of pads of emitters that drift from its intended phosphor (28) are encouraged to drift toward an adjacent phosphor (28) of the same color.

Abstract: A field emission device manufactured by the disclosed method and employed in a display unit includes a glass substrate, an emitter electrode formed on the glass substrate, a carbon nanotube (CNT) emitter formed on the emitter electrode, and a gate stack formed around the CNT emitter. Electron beams are extracted from the CNT emitter and the extracted electron beams are focused onto a given position. The gate stack includes a mask layer that covers the emitter electrode provided around the CNT emitter, a gate insulating layer and a gate electrode sequentially formed on the mask layer, a focus gate insulating layer having double inclined planes facing the CNT emitter on the gate electrode, and focus gate electrode coated on the focus gate insulating layer.

Abstract: The invention provides an electron beam device 1 comprising at least one field emission cathode 3 and at least one extracting electrode 5, whereby the field emission cathode 5 comprises a p-type semiconductor region 7 connected to an emitter tip 9 made of a semiconductor material, an n-type semiconductor region 11 forming a pn-diode junction 13 with the p-type semiconductor region 7 a first electric contact 15 on the p-type semiconductor region 7 and a second electric contact 17 on the n-type semiconductor region 11. The p-type semiconductor region 7 prevents the flux of free electrons to the emitter unless electrons are injected into the p-type semiconductor region 7 by the pn-diode junction 13. This way, the field emission cathode 3 can generate an electron beam where the electron beam current is controlled by the forward biasing second voltage V2 across the pn-diode junction. Such electron beam current has an improved current value stability.

Abstract: An active matrix display that does not require a transistor or similar current switching device at each pixel. Instead, the display employs in each pixel a temperature-controlled current source that provides to the field emitters of the pixel an amount of electrical current which varies in response to the temperature of a temperature sensor. Each pixel further includes a thermoelectric heat transfer circuit which transfers heat to or from the sensor in an amount which varies in response to the video signal. Consequently, the video signal controls the temperature of the sensor within a pixel's temperature-controlled current source, which controls the current flow through the pixel's field emitters.

Abstract: A field emission type cold cathode, comprising a substrate having a conductivity at least on the surface thereof, an insulation layer formed on the substate and having a first opening part, a gate electrode layer formed on the insulation layer, having a center generally aligned with the center of the first opening part, and having, therein, a second opening part having an opening diameter larger than the opening diameter of the first opening part, and an emitter layer formed in the first opening part, the emitter layer characterized by further comprising the bottom surface and the side surfaces of the first opening part.

Abstract: A microelectromechanical microwave vacuum tube device is disclosed. The device consists of a cathode formed on a substrate, the cathode comprising electron emitters. A cathode emission control grid is also attached to the device substrate. The device further includes an output structure where amplified microwave power is removed from the device. In the device, the cathode surface and the grid surface are substantially parallel to each other and substantially perpendicular to the substrate. One of either the cathode, the grid, or both the cathode and the grid, are attached to the device substrate by one or more flexural members. The device further comprises an anode that is substantially parallel to the cathode surface and the grid surface.

Abstract: Diamond microtip field emitters are used in triode vacuum microelectronic devices, sensors and displays. Diamond triode devices having integral anode and grid structures can be fabricated. Ultra-sharp tips are formed on the emitters in a fabrication process in which diamond is deposited into mold cavities in a two-step deposition sequence. During deposition of the diamond, the carbon graphite content is carefully controlled to enhance emission performance. The tips or the emitters are treated by post-fabrication processes to further enhance performance.

Abstract: An electron emission device can include gate electrodes formed on a substrate and cathode electrodes insulated from the gate electrodes with an insulating layer interposed between them. Each cathode electrode can have a receptor at a peripheral side. Electron emission regions may be formed within the receptors and in contact with the cathode electrodes. Counter electrodes can face the cathode electrodes, can be coplanar with the cathode electrodes, and can be coupled to the gate electrodes. The shortest distance between the electron emission region and the counter electrode may be smaller than the shortest distance between the cathode electrode and the counter electrode.

Abstract: A luminescent brightness compensation of sub-pixels of tri-electrode based field-emission display. The cathode conductive layers corresponding to sub-pixels constituting a pixel are arranged at various levels according to the respective luminescent efficiencies thereof. Thereby, the color with lower or higher luminescent efficiency obtains a stronger or weaker electric field between anode and cathode, respectively. Therefore, the different luminescent efficiency of three sub-pixels with primary color is compensated.

Abstract: A self-aligned gated field emission device and an associated method of fabrication are described. The device includes a substrate and a porous layer disposed adjacent to the surface of the substrate, wherein the porous layer defines a plurality of substantially cylindrical channels, each of the plurality of substantially cylindrical channels aligned substantially parallel to one another and substantially perpendicular to the surface of the substrate. The device also includes a plurality of substantially rod-shaped structures disposed within at least a portion of the plurality of substantially cylindrical channels defined by the porous layer and adjacent to the surface of the substrate, wherein a portion of each of the plurality of substantially rod-shaped structures protrudes above the surface of the porous layer.

Abstract: Described herein is a resistor layer for use in field emission display devices and the like, and its method of manufacture. The resistor layer is an amorphous silicon layer doped with nitrogen and phosphorus. Nitrogen concentration in the resistor layer is preferably between about 5 and 15 atomic percent. The presence of nitrogen and phosphorus in the silicon prevents diffusion of Si atoms into metal conductive layers such as aluminum, even up to diffusion and packaging temperatures. The nitrogen and phosphorus also prevent defects from forming at the boundary between the resistor layer and metal conductor. This leads to better control over shorting and improved resistivity in the resistor.

Abstract: In accordance with the inventions, a new configuration of spaced-apart nanostructures is provided as well as a variety of improved articles using the new configuration. Improved articles include microwave amplifiers, field emission displays, plasma displays, electron sources for lithography and compact x-ray sources.

Abstract: The field emission device includes a substrate, a cathode, a gate insulating layer, an electron emitter, and a gate electrode. The cathode is formed on the substrate. The gate insulating layer is formed on the cathode and has a well exposing a portion of the cathode. The electron emitter is formed on the exposed portion of the cathode. The gate electrode is formed on the gate insulating layer and has a gate hole corresponding to the well. The gate electrode further includes a cylindrical electrode part that forms a focusing electric field from the gate hole toward a proceeding path of an electron beam. Accordingly, a focusing electric field can be formed around an electron beam emitted from the electron emitter so as to converge and focus the electron beam passing through the focusing electric field. As a result, color purity, brightness, and durability can be improved.

Abstract: A light source has a rear glass substrate and a front glass substrate having a plate surface disposed in facing relation to a principal surface of the rear glass substrate. The plate surface of the front glass substrate is coated with a phosphor. A two-dimensional array of electron emitters is disposed on the principal surface of the rear glass substrate. A space defined between the rear glass substrate and the front glass substrate is filled with a gas. The gas may be an Hg (mercury) gas or an Xe (xenon) gas.

Abstract: A field emission type backlight device can include upper and lower substrates facing each other with a gap between them, an anode electrode on a lower side of the upper substrate, a fluorescent layer on a lower side of the anode electrode, a lower gate electrode on an upper side of the lower substrate, an insulating layer on an upper side of the lower gate electrode, a cathode electrode on an upper side of the insulating layer, and a gate electrode that is provided on an upper side of the insulating layer and electrically connected to the lower gate electrode.

Abstract: An image-forming device having, in an envelope, an electron-emitting element, an image-forming member for forming an image by irradiation of an electron beam emitted from the electron-emitting element, and an electroconductive supporting member for supporting the envelope. The potential of the supporting member is controlled to not be higher than the maximum potential applied to the electron-emitting element. The electron-emitting element and the image-forming member can be placed in juxtaposition on the same substrate, an electro-conductive substrate can be additionally provided in opposition to the face of the substrate, and the supporting member can be connected electrically to one of the electrodes and also to the electro-conductive substrate.

Abstract: A front substrate of an image display device has a phosphor screen and a metal back layer superposed on the phosphor screen. A plurality of electron emitting elements which emit electrons toward the phosphor screen are located on a rear substrate opposed to the front substrate. The metal back layer has a region which corresponds to the phosphor screen and is divided by gaps g1 in a first direction and gaps g2 in a second direction perpendicular to the first direction such that there are relations g1<g2, and ?g1<?g2, where ?g1 and ?g2 are sheet resistances at the gaps g1 and g2, respectively.

Abstract: A field emission display includes: a cathode electrode (17); an anode electrode (20); a gate electrode (19) arranged between the cathode electrode and the anode electrode; a carbon nanotube array (15) electrically connected to the cathode electrode at a first end; and a spacer (14) insulatively separating the gate electrode from the cathode electrode. A second opposite end of the carbon nanotube array is flush with a top end of the spacer. An intermediate layer (11) having a precisely controllable thickness is arranged between the gate electrode and the spacer. The distance between the gate electrode and the carbon nanotube array is mainly controlled by the thickness of the intermediate layer.

Abstract: A field emission display (FED) includes first and second substrates opposing one another with a predetermined gap therebetween. The FED also includes cathode electrodes formed in a stripe pattern on the first substrate, and a plurality of electron emission sources formed on the cathode electrodes; gate electrodes formed on the first substrate in a state insulated from the cathode electrodes and the electron emission sources by an insulating layer; and anode electrodes formed on a surface of the second substrate opposing the first substrate, and including phosphor layers formed thereon. A pair of fixing rails are formed along two opposing edges of one of the first and second substrates, the fixing rails having undergone a blackening process; and a metal grid provided between the first and second substrates and welded to an upper surface of the fixing rails.

Abstract: A method and a structure for a converging-type electron-emission source of a field-emission display are disclosed. A substrate is provided, and a silver paste is used to form a first electrode layer on the substrate by the process such as thick-film photolithography or screen-printing. A carbon nanotube is formed on the first electrode layer by thick-film photolithography or screen-printing, and a second electrode is formed on the carbon nanotube. A third electrode layer is formed on the first electrode layer around the second electrode layer by thick-film photolithography or screen-printing. The third electrode layer is higher than the second electrode layer, such that a converging exit is formed around the second electrode layer. A sintering step is performed. When the electron beam is generated, the electron beam is concentrated at the center of the converging exit to impinge a phosphor layer of an anode without causing gamut.

Abstract: A stable field-emission electron source that does not suffer from a current drop even after a high-current density operation for a long time is provided. The field-emission electron source includes: a substrate; an insulating layer that is formed on the substrate and that has a plurality of openings; cathodes arranged at the respective openings in order to emit electron beams; a lead electrode formed on the insulating layer in order to control emission of electrons from the respective cathodes; and a surface-modifying layer formed on the surface of each of the cathodes emitting electrons, comprising a chemical bond between a cathode material composing the cathodes and a material different from the cathode material.

Abstract: A double-sided display device includes a pair of substrates, on which self-emitting elements are formed respectively, being bonded to each other. A lead wiring section of the self-emitting element area formed on one of the substrates and a lead wiring section of the self-emitting element area formed on the other substrate are formed on the same side of the substrates. Each of the lead wiring sections is formed in a part of the side of each of the substrates. In addition, cutout portions are formed in parts of the sides of the substrates where the lead wiring sections are not formed. Thus, in the double-sided display device, the lead wiring sections formed on ends of substrates can be easily connected with a driving circuit component, a wiring substrate or the like, while the space for the double-sided display device can be reduced.

Abstract: A field emission display device includes three parts: a cathode emitter unit, an electron amplification unit, and a faceplate unit. The primary emission of electrons emitted from the cathode emitter unit bombards an electrode layer that includes an electron amplification material in order to generate secondary emissions of electrons. The secondary emissions of electrons bombard a light-emitting layer of the faceplate unit to generate fluorescence. Then, the fluorescence is transmitted through a transparent faceplate for viewing.

Abstract: An electron emitter is formed by in situ growth from the vapor on catalyst clusters that are adhered by an adhesion layer to a conductive electrode. The emitter comprises hemispheroidal nanofiber clusters that emit electrons at low field strengths and high current densities, producing bright light by the interaction of the electrons and a fluorescent and/or phosphorescent film on an anode spaced across an evacuated gap. The nanofibers may be grown such that the nanofiber clusters are entangled, restricting movement of individual nanofibers.

Abstract: A light-emitting cell, includes a light-emitting material which can emit light in response to a collision of an electron beam; an electron-emitting unit having a carbon nanotube as an electron source for releasing the electron beam and emitting the electron beam to ram against the light-emitting material; and a gate disposed above the carbon nanotube for controlling the electron beam emitting from the carbon nanotube whether to pass through the gate to ram against the light-emitting material at a specific address wherein the gate comprises a network conductor including a first metal layer for determining an x-coordinate of the address, a second metal layer for determining a y-coordinate of the address, and an extracting electrode placed between the carbon nanotube and the first metal layer for extracting the electron beam from the carbon nanotube.

Abstract: The present invention provides an emissive flat panel display device which is capable of performing a gate operation at a relatively low voltage of several V to several tens V using gate electrodes. In the emissive flat panel display device which includes a back panel which is constituted of a back substrate on which cathode electrodes having electron sources formed of carbon nanotubes and gate electrodes are formed, a face panel which forms phosphors and anode electrodes thereon, and a sealing frame which seals the back panel and the face panel, the difference between an electric field strength Emax for allowing the electron sources to obtain the required maximum emission current density and an electric field strength Emin which becomes the minimum emission current density is set to 1V/?m or less, and preferably 0.5V/?m or less.

Abstract: A field emission backlight device may include a first substrate and a second substrate separate from and roughly parallel to each other, a first anode electrode and a second anode electrode that face each other on inner surfaces of the first substrate and the second substrate, and cathode electrodes separate from and roughly parallel to one another between the first substrate and the second substrate. It may also include electron emission sources disposed on the cathode electrodes to emit electrons by an electric field and a phosphorous layer disposed on the first anode electrode or the second anode electrode.

Abstract: A field emission type display device has a structure in which each pixel is constituted of a combination of a plurality of small apertures and a plurality of small electron sources. Due to such a constitution, it is possible to reduce undesired impact of electrons on control electrodes and the enhancement of the heat resistance of the carbon nanotubes of electron sources, whereby it is possible to obtain a display device of high quality and long lifetime, while exhibiting a high-performance electron emission characteristic. Boron (B) is adhered to carbon nanotubes, which constitute electron sources, through the small apertures of the control electrodes; and, hence, the alignment of the small apertures and the small electron sources is ensured and the area of the electron source is set to be equal to or less than the area of the aperture.

Abstract: To detect a dark current when an abnormal discharge occurs between an anode and respective electrodes, on an inner surface of a front substrate, a dark current detection electrode is formed in a state that the dark current detection electrode is positioned adjacent to the outside of a screen display region on which an anode is formed and on a plane substantially equal to a plane on which the anode is formed. Then, between an electrode terminal of the dark current detection electrode and a ground, an ammeter which detects the flow of a dark current and a DC power source having a preset voltage value which is more or less lower than a high voltage supplied to the anode are connected in series.

Abstract: In a field emission display device, an opening dimension in a predetermined direction (or x direction) of an opening of a control electrode is greater than an opening dimension in the predetermined direction of an electron pass aperture of a shield electrode, and the shield electrode is located at the front of the control electrode so that the entire range of the opening dimension in the predetermined direction of the electron pass aperture is within the range of the opening dimension in the predetermined direction of the opening of the control electrode.

Abstract: An improved thermionic cathode is provided. The cathode has a carbon-coated cone surface and reduced cone angle (e.g. typically 60 degrees or less) that delivers an electron beam with high angular intensity and brightness and exhibits increased longevity.

Abstract: Provided is a field emission display (FED) with a carbon nanotube emitter and a method of manufacturing the same. A gate stack that surrounds the CNT emitter has a mask layer that covers an emitter electrode adjacent to the CNT emitter, and a gate insulating film, a gate electrode, a focus gate insulating film (SiOx, X<2), and a focus gate electrode formed on the mask layer. The focus gate insulating film has a thickness 2 ?m or more, and preferably 3˜15 ?m and is preferably made using PECVD. A flow rate of silane and nitric acid for forming the focus gate insulating film and/or the gate insulating film are maintained at 50˜700 sccm and 700˜4,500 sccm, respectively. By doing so and by making the oxide thick, the oxide is less apt to crack and thus less apt to generate a leakage current.

Abstract: Side faces of anodes have a tapered incline that becomes broader toward a lower layer. Thus, an emissive element layer is smoothly formed on the anodes making it possible to prevent field contraction of the electric field. An EL display apparatus having long life and high yield is provided by preventing the emissive element layer from rupturing between an anode and a cathode and by preventing concentration of the electric field at an upper edge of the anode facing the cathode and localized deterioration in the emissive element layer.

Abstract: A network conductor has an irregular network structure with as thin lines as 10 nm to 10 ?m. The network conductor is obtained by forming a thin film on a substrate; forming microcracks in a network manner in the thin film; and forming a layer of a conductive material in the microcracks. The network conductor can be used for a positive electrode and/or a negative electrode of an organic electroluminescence device.

Abstract: A fabrication method for an emitter includes the steps of forming on a glass substrate a CNT film which contains a plurality of carbon nanotubes (CNTs) and constitutes an emitter electrode, forming a gate electrode via an insulating film on the CNT film, forming a plurality of gate openings in the gate electrode and the insulating film, and aligning upright the CNTs in the gate opening. The upright alignment generates a stable uniform emission current and provides excellent emission characteristics.

Abstract: A triode structure of a field emission display and fabrication method thereof. A plurality of cathode layers arranged in a matrix is formed overlying a dielectric layer. A plurality of emitting layers arranged in a matrix is formed overlying the cathode layers, respectively. A plurality of lengthwise-extending gate lines is formed on the dielectric layer, in which each of the gate layers is disposed between two adjacent columns of the cathode layers.

Abstract: A field emission device for use as a backlight of a liquid crystal display comprises a conductive anode having a light-emitting layer and a cathode separated from the anode by a spacer. The cathode comprises nanofiber electron emitters. For example, the nanofiber electron emitters comprise a substrate, a conductive film adhered to the substrate and a plurality of isolated, hemispheroidal nanofiber clusters that are capable of emitting electrons at high current density and low field strength.

Abstract: A triode structure of a field emission display and fabrication method thereof. A plurality of cathode layers arranged in a matrix is formed overlying a dielectric layer. A plurality of emitting layers arranged in a matrix is formed overlying the cathode layers, respectively. A plurality of lengthwise-extending gate lines is formed on the dielectric layer, in which each of the gate layers is disposed between two adjacent columns of the cathode layers.

Abstract: A structure of a coplanar gate-cathode of triode CNT-FED and a manufacturing method thereof by Imprint Lithography and ink jet. The structure includes a substrate, a plurality of cathode layers, a plurality of gate extended layers, a plastic dielectric layer, a plurality of dielectric openings, and a plurality of gate electrodes. The plurality of cathode layers and the plurality of gate extended layers are coplanar, and formed on the substrate by Imprint Lithography and the plurality of dielectric openings are made by Imprint Lithography. The gate electrode, made by ink jet or screen print, can be extended through the plastic dielectric layer to the gate extended electrode to feature the coplanar gate-cathode.

Abstract: Systems and methods are described for individually electrically addressable carbon nanofibers on insulating substrates. A method includes forming an electrically conductive interconnect on at least a part of an insulating surface on a substrate; and growing at least one fiber that is coupled to the electrically conductive interconnect.

Abstract: A field emission device having emitter tips and a support layer for a gate electrode is provided. Openings in the support layer and the gate layer are sized to provide mechanical support for the gate electrode. Cavities may be formed and mechanically supported by walls between cavities or columns within a cavity. Dielectric layers having openings of different sizes between the emission tips and the gate electrode can decrease leakage current between emitter tips and the gate layer. The emitter tips may comprise a carbon-based material. The device can be formed using processing operations similar to those used in conventional semiconductor device manufacturing.

Abstract: An electron emission device and/or display using the same includes a beam-focusing structure. The beam-focusing structure has a first insulating layer formed on a plate. The first insulating layer has a thickness, and is formed with a first hole. A first electrode is formed on the first insulating layer and extending into the first hole. An emission portion is formed in the first hole and connected to the first electrode. A second insulating layer is formed on the first electrode and is also formed with a second hole through which the emission portion is at least partially exposed. A second electrode is formed on the second insulating layer. In the electron emission device and/or the display, an electric field between the first electrode and the second electrode causes the emission portion to emit an electron beam and focuses the electron beam from the emission portion.

Abstract: A tetraode field-emission display and a method of fabricating the same are disclosed. A mesh is disposed between an anode plate and a cathode plate. The mesh has a gate layer and a converging electrode layer separated by an insulation layer to form a sandwich structure. The mesh has a plurality of apertures in correspondence with each set of anode and cathode. The converging electrode layer is facing the anode plate, such that the divergent range of an electron beam emitted by an electron emission source can be restricted. Thereby, the electron beam can impinge the corresponding anode more precisely.

Abstract: A fluorescent display tube including: (a) a substrate having a display surface; (b) anodes formed on the display surface of the substrate, and spaced apart each other; (c) cathodes capable of generating electrons; (d) fluorescent layers each of which is fixed to a corresponding one of the anodes; (e) a rib formed on the display surface of the substrate so as to surround a periphery of each of the fluorescent layers; and (f) a control electrode fixed to an upper end face of the rib, and consisting of a plurality of sections which are spaced apart each other; wherein the fluorescent layers are selectively activated by the control electrode, so as to be struck by the electrons generated by the cathodes, for emitting light, wherein the rib includes continuous wall portions continuously extending along respective boundaries each of which is located between a corresponding pair of the anodes which are adjacent to each other, such that each pair of the anodes are electrically insulated from each other, and wherein t