Abstract: A field emission element features an emitter which has rectangular projections at its distal end capable of readily controlling the interval between electrodes in increments as small as sub-microns, in order to reduce the voltage at which the device starts field emission at the required level and to improve emission uniformity. An emitter (2,20), a collector (3,21) and a gate (5,22) are arranged on a substrate (1), which is formed with a recess (4) in proximity to the electrodes (2,3,20,21) other than the gate (5). The gate (5) is provided in the recess (4).

Abstract: A fluorescent display device (1) includes an air tight envelope (2) having a cathode substrate (3), an anode substrate (4) with a phosphor layer arranged to provide a luminous display, a seal member (5), an evacuation hole (9) formed at a side of the envelope (2), and a getter chamber (10) in communication with the hole (9). The getter chamber (10) is disposed on the outside of the envelope (2) and includes a chamber body (12), and an evacuation tube (13). The getter chamber (10) eliminates the independent formation of an evacuation hole in the cathode substrate (3), and thereby prevents damage and contamination of the cathode substrate (3).

Abstract: A flat-type fluorescent display device permitting luminous display to be observed through only a front glass cover while substantially increasing luminance. A front glass cover is provided on an inner surface thereof with FECs constituted by cathode lines, insulating layers, emitters and gate lines so as to define light-permeable sections between FECs. A substrate is formed opposite to the light-permeable sections with anodes constituted by anode-lines and phosphor layers. Electrons emitted from the FECs impinge on the anodes, leading to luminescence of the phosphor layer, which is then observed through the light-permeable sections of the front glass cover.

Abstract: A phosphor is disclosed which is suitable for use for a fluorescent display device and driven at a driving voltage as low as 1 kV or less and free of S and Cd. Compounds of Ti, alkaline earth metal and an element of Group 13 of the periodic table in predetermined amounts are heated at 1100.degree. to 1400.degree. C. for calcination, resulting in a solid solution of the rare earth element and one element of Group 13 being formed in a phosphor matrix made of an oxide of alkaline earth metal and Ti. An example of the phosphor is SrTiO.sub.3 :Pr,Al exhibiting a red luminous color.

Abstract: A field emission cathode capable of reducing an operation voltage and substantially preventing damage of an emitter. An emitter is provided on a substrate. The emitter includes a base and a plurality of rectangular tips projecting from the base. A gate is arranged in a recess formed on the substrate so as to be in proximity to the emitter. A width a of the tips of the emitter and an interval b between the tips are defined to satisfy a relationship of b/a=2. This permits an electric field strength applied to the tips of the emitter to be substantially increased as compared in a conventional field emission cathode of b/a.ltoreq.1, resulting in an operation voltage being reduced and a sufficient amount of emitter current being produced.

Abstract: A field emission cathode device capable of permitting when short-circuiting occurs between any of emitters and a gate, a block in which the block is formed to be separated from the remaining blocks and preventing a material fused at the time of the short-circuiting from scattering. A cathode conductor arranged on a substrate is formed with a plurality of cutouts, in which resistive layers are arranged. The resistive layers each are provided with terminals through which the resistive layer is connected to the cathode conductor. An insulating layer is arranged so as to cover the resistive layers and cathode conductor and a plurality of emitters are formed on each of the resistive layers. A gate conductor is formed on the insulating layer so as to be positioned around a distal end of each of the conical emitters. Short-circuiting between any of the emitters and the gate conductor causes the terminals to be fused. The insulating layer prevents the fused material from scattering.

Abstract: A field emission type display device capable of providing display with gradation and permitting the whole display device to be integrated with a display drive circuit section. Memory sections are arranged in correspondence to image cell sections, resulting in static display being accomplished. Also, Light emission of an anode is carried out depending on data held in the memory section, so that a luminous period is increased and adequate luminance is provided at a drive voltage substantially lower than that required for dynamic display. An FEC element is incorporated in each of the memory sections in correspondence to incorporation of an FEC element in each of the image cell sections, so that the image cell sections and memory sections may be concurrently manufactured during manufacturing of the FEC elements, to thereby significantly simplify manufacturing of display device.

Abstract: A process for manufacturing a field emission element including a substrate, and an emitter and a gate each arranged on the substrate is provided. The emitter is formed at at least a tip portion thereof with an electron discharge section, which is formed of metal or semiconductor into a monocrystalline structure or a polycrystalline structure preferentially oriented in at least a direction perpendicular to the substrate by deposition.

Abstract: A method for manufacturing a display device is available that is capable of remarkably improving life characteristics of a display device. A display device placed in a chamber is evacuated to about 10.sup.-7 Torr. Then, reducing gas is introduced into the display device and held therein for several minutes, followed by evacuation of the display device to about 10.sup.-5 Torr. The reducing gas introducing and discharge steps are repeated several times. Thereafter, evacuation of the display device is carried out while keeping the chamber at about 300.degree. C., followed by sealing of the display device.

Abstract: A phosphor capable of exhibiting luminescence with high efficiency by excitation due to impingement of electrons accelerated under an anode voltage of hundreds volts to about 2 kV thereon and a method for preparing the same are disclosed. Mn is ion-implanted in ZnGa.sub.2 O.sub.4 which is a matrix crystal of the phosphor deposited on a substrate. Three kinds of implantation energy of 150 keV, 90 keV and 30 keV are selected and the ion implantation is effected three times in the order of the level of the implantation energy. A concentration of Mn is rendered substantially constant within a depth range between 100 angstrom and 1000 angstrom of a depth of 2000 angstrom or less in a luminous region of the phosphor. The ion implantation thus carried out three times permits the phosphor to exhibit increased luminous efficiency as compared with one-time ion implantation.

Abstract: A low-velocity electron excited phosphor having a composition represented by a general formula ZnO.multidot.(Al.sub.x, Ga.sub.l-x).sub.2 O.sub.3 :Mn, wherein X=0.001 to 0.3 mol. A content of Al in the phosphor is set be to within a range between 0.001 mol and 0.3 mol. The range permits a variation in luminance of the phosphor to be within .+-.30% and initial luminance of the phosphor to be significantly increased, resulting in the phosphor being suitable for use for a fluorescent display device.

Abstract: A low-velocity electron excited phosphor capable of exhibiting increased luminance and a method for producing the same. A matrix crystal for the phosphor is doped therein with an activator at implantation energy of 50 KeV by ion implantation, resulting in the activator entering a portion of the matrix crystal extending to a depth as small as 0.5 .mu.m from a surface thereof. Then, the phosphor is annealed for a reduced period of time as short as 10 seconds at a temperature of 900.degree. C. Such short-time annealing effectively prevents distribution of the activator in the matrix crystal formed during the implantation from being deeply spread into the matrix crystal by thermal diffusion. Thus, the activator concentratedly exists at only a portion of the matrix crystal in proximity to the surface thereof. Thus, the phosphor exhibits increased luminance as compared with a prior art, because luminescence of the phosphor is limited to the portion thereof in proximity to the surface.

Abstract: An evacuation apparatus is capable of evacuating an envelope to a high vacuum without evacuating a whole room or chamber to a high vacuum. An evacuation pipe is connected at a distal end thereof to an evacuation head and a vacuum pump is actuated to evacuate an evacuation chamber to a high vacuum, to thereby evacuate an envelope to a high vacuum. Then, a motor is driven to rotate ball screws, to thereby upwardly move the envelope mounted on the evacuation head. The evacuation pipe is fused at an intermediate portion thereof by a gas burner, to thereby be sealed. Then, the evacuation pipe is cut to disconnect the envelope from the evacuation head.

Abstract: A field emission element including a gate and an emitter and capable of preventing any of the element oxide layer from being formed on a tip of the emitter to prevent a decrease in emission current, unstable operation and an increase in noise. The gate has a surface formed of a material of oxygen bonding strength higher than that of a material for at least a tip surface of the emitter, so that oxygen atoms and molecules containing oxygen entering the gate may be captured by adsorption on the gate to prevent formation of any oxide layer on the emitter. When a portion of the emitter other than the tip surface is formed of a material of oxygen bonding strength higher than that of the material for the tip surface, formation of any oxide layer on the tip surface of the emitter is minimized.

Abstract: A field emission cathode capable of permitting a display to be carried out at increased density and a circuit incorporated therein together with an FEC to exhibit satisfactory characteristics and being driven according to a static drive system. A plurality of control lines and data wires are arranged in a matrix-like manner on a monocrystalline Si substrate, to thereby form element regions on the substrate. The element regions each are formed therein with a circuit element, on which a field emission section is laminated. The circuit elements each include a first transistor connected to both data wire and control wire and functioning as a switching element, a capacitor serving as a circuit for storing therein a signal input thereto, and a second transistor for amplifying a signal input thereto and feeding it to the field emission section.

Abstract: A field emission element in which the emitter has rectangular projections at its distal end capable of readily controlling the interval between electrodes in increments as small as sub-microns, in order to reduce the voltage at which the device starts field emission at the required level and to improve emission uniformity. An emitter (2,20), a collector (3,21) and a gate (5,22) are arranged on a substrate (1), which is formed with a recess (4) in proximity to the electrodes (2,3, 20,21) other than the gate (5). The gate (5) is provided in the recess (4).

Abstract: A powder agitator used for an ion implantation device or an ionized beam deposition device capable of exhibiting satisfactory powder agitating characteristics and minimizing positive charging on powders. The powder agitator includes a base, a vessel for receiving powders therein, a plurality of supports for supporting the vessel on the base, and a pair of piezoelectric elements arranged on the supports and functioning as a vibration generating section. Application of a voltage to the piezoelectric elements causes the vessel to be oscillated in a direction of rotation of the vessel and a speed of oscillation of the vessel to be varied depending on a direction of oscillation of the vessel, resulting in agitating the powders in the vessel.

Abstract: An image display device capable of minutely setting the interval between an emitter (6) and a gate (5) with high accuracy and of being driven at a significantly reduced drive voltage with good emission uniformity. Each emitter (6) is provided in a recess in a substrate (2), so that the interval between the emitter (6) and a gate (5) is determined depending upon the thickness of the emitter (6). Thus, the interval can be readily controlled by adjusting or varying the period of time during which the film for the emitter (6) is formed, resulting in a micro-interval of the order of sub-microns between the two components being possible with high accuracy.

Abstract: An electron emitting element capable of preventing pollution of the emitter due to absorption of gas thereon, to thereby ensure stable emission of electrons over a long period of time even in a low vacuum atmosphere. The electron emitting element is constructed so as to permit a part of electrons emitted from one of emitters to impinge on the other of the emitters being ready for emission to clean it.

Abstract: An electron feeder for a flat-type luminous device capable of providing electrons sufficient to ensure the uniform luminance of a whole display section irrespective of a distance from an electron source. A plurality of front electrodes and a plurality of rear electrodes constituting an electron beam guide are arranged separate from one another in the direction of traveling of the electrons, respectively, and the front electrode and rear electrode corresponding to each other constitute each guide electrode section. The so-constructed guide electrode sections are alternately applied thereto two different voltages, resulting in the electron beam guide exhibiting the function of focusing electrons.