Abstract: The present invention provides a method for preparing an ion optical device. A substrate is fabricated with a hard material adapted for a grinding process, the substrate at least including a planar surface, and including at least one insulating material layer. Next, one or more linear grooves are cut on the planar surface, to form multiple discrete ion optical electrode regions on the planar surface separated by the linear grooves. Then, conductive leads are fabricated on other substrate surfaces than the planar surface and in a through hole inside the substrate, to provide voltages required on ion optical electrodes. By using high-hardness materials in cooperation with high-precision machining, higher precision and a desired discrete electrode contour can be obtained.

Abstract: A fluorescent tube 30 of the present invention includes a glass tube 31 and electrodes 32 opposed to each other on both end portions 31a of the glass tube 31, characterized in that the electrode 32 has a closed-end hollow shape opened on the opposite side from the end portion 31a of the glass tube 31, and the electrode 32 constituting the closed-end hollow shape has an inner surface 35 configured to be tapered toward the end portion 31a of the glass tube 31. With this configuration, it is possible to contain accelerated electrons not only in the bottom face 33 of the electrode 32 but also in the inner surface 35 of the electrode 32, thereby suppressing sputtering. Consequently, it is possible to increase the life of the fluorescent tube 30.

Abstract: An image-forming apparatus includes a vacuum container having a first plate and a second plate arranged opposite to the first plate, an electron source disposed on the first plate and provided within the vacuum container, and an image-forming member disposed on the second plate within the vacuum container and irradiated with an electron emitted from the electron source. An airtight lead-in terminal has a first end in electrical contact with the image-forming member and a second end leading outside of the vacuum container through a hole in the first plate. The second end leading outside of the vacuum container is held and fixed so as not to protrude from an outer surface of the first plate.

Abstract: An apparatus for an electron gun includes a one piece thermionic electron source that extends in a longitudinal direction and has opposite end portions, an aperture disposed therebetween, and two longitudinal portions that extend in the longitudinal direction and are spaced apart from one another by the aperture and rigidly joined together by the opposite end portions. The thermionic electron source is less susceptible to ion bombardment and therefore has a longer operating life than previous ribbon type electron sources. Further, because the electron source is one piece, it does not require support and relative positioning of multiple emitters such as that required by an electron source having two separate and parallel emitters.

Abstract: Positive ions which are generated in a vacuum tube (1) and can adversely affect the electron emission of a cathode (3) are collected for the major part by a screen grid or diaphragm (5), which forms part of a positive electron lens (4,5). In the case of a semiconductor cathode having a circular emission region (13) having a diameter larger than that of the opening in the screen grid (5), this emission region (13) is struck only by positive ions generated in a small region between the cathode (3) and a first grid (4). These ions moreover have a comparatively low energy so that the emission behavior is to only a limited extent adversely affected by sputtering by positive ions which would remove cathode material (33), such as cesium.

Abstract: An improved ion clearing electrode assembly for use in an electron beam production and control assembly which is especially suitable for use in a scanning electron beam computed tomography X-ray scanning system. The assembly uses a vacuum sealed housing chamber which is evacuated of internal gases and in which the electron beam is generated and propagated. Normally residual gas within the chamber interacts with the electrons of the beam to produce positive ions which have the affect of neutralizing the space charge of the electron beam and thereby causing focusing difficulties and destabilization of the beam. The ion collecting electrodes herein are an improvement of those disclosed in the co-pending Rand U.S. patent application Ser. No. 434,252, now U.S. Pat. No. 4,521,900. The electrodes are designed to extract the ions and reduce their neutralizing effect while maintaining a precisely uniform electric field and therefore beam optical aberrations are minimized.

Abstract: A color picture tube with an in-line multi-stage focusing type electron gun assembly which can suppress generation of spark discharges and which can be improved in withstand voltage characteristics. The electron gun assembly comprises a metallic shielding member facing the fluorescent screen and maintained at the anode potential. The shielding member is displaced, in the direction of a tube axis and toward the base, from an edge facing the base of an inner graphite coating formed on the inner wall of the neck tube by a predetermined distance or more. The metallic shielding member shields electrostatically the edge of the inner graphite coating from the grid electrodes and cathode electrode close to the base and at lower potentials. At least one of focusing voltage feed conductors for third and fifth grid electrodes is wired so as to run through a gap between the inner wall of the neck tube and a bead glass for supporting the electrodes of the electron gun assembly.

Abstract: An electrostatic beam deflection system is provided for use in electron beam devices. In the present system several grids and an accelerating electrode are geometrically configured to direct positive ions away from an electron emitter surface. These positive ions are typically formed by interaction of the electrons emitted from the emitter surface with a gas ambient or with species adsorbed on the various grids and electrodes. Degradation of the electron emitter surface is thereby reduced, and the lifetime of the emitter concomitantly extended.

Abstract: An electron beam forming structure includes an anode having first and second sections spaced from each other with the first section being closest to the cathode and having a beam-admitting aperture and being connected to a positive potential and the second section having a beam-limiting aperture and being connected to ground relative to the first section. The first section will repel positive ions created in an area adjacent the beam-limiting aperture and deflect them away from the source of the electron beam so they can be collected at the second section.