U.S. Philips Corporation

Horst Seifert

Bernhard N Lersmacher

Johannes Wilhelmus Krol

Hans J Lydtin

Bernd Offerman

Reinhard Ziegler

Rudolf Bachmor

Stefan Grote

The invention relates to a cathode ray tube having an input resonator cavity which includes a first metal wall (2) and, spaced apart therefrom, a second metal wall (3) each conveying a low electric potential and constituting coupling areas (6, 7) at axially spaced locations, in which areas metal elements (10, 12) conveying a high electric potential are located opposite surface sections (8, 9 and 14, 15) which are electrically connected to the metal walls (2, 3) via insulating dielectrics (11, 13), the coupling areas (6, 7) being separated by a spacing dielectric. A high-voltage stable arrangement which is resistant to temperature fluctuations is obtained in that the spacing dielectric consists of a different material than the insulating dielectrics (6, 7) and has a lower value of the product of loss factor and dielectric constant (tg.delta..times..epsilon.) at a high frequency.

Cathode ray tube having an input resonator cavity

A multistage collector for electron-beam tubes, in particular for klystrons, comprising a plurality of electrode rings (7 to 11 ) which are arranged one behind the other in the direction of the electron beam and which are connected to gradually decreasing electric potentials, and comprising insulating ceramic spacer rings (12 to 16) which interconnect adjacent electrode rings (7 to 11) in an electrically insulating vacuum-tight manner. Flashovers between the collector stages are precluded in that radially outwardly extending first ring-shaped metal casings (19, 20), which can be manufactured in a simple manner are soldered in a vacuum-tight manner to the end regions of the spacer rings (12 to 16), and in that second ring-shaped metal casings (21, 22) are soldered in a vacuum-tight manner to the electrode rings (7 to 11), an annular disc area (21a, 22a) of each of said ring-shaped casings engaging an associated annular disc area (19a, 20a) of a first ring-shaped casing (19, 20) and said annular disc areas being welded together in a vacuum-tight manner, so that two welding collars are formed, and in that the ambient air-accessible outer surfaces of the ring-shaped metal casings (19 to 22) and hence the welding collars are covered by an insulating material.

Multistage collector for electron-beam tubes having collector electrodes

Cathodes having a support for emissive material of foamed carbon are mechanically stable and resistant to detrition and have a homogeneous pore distribution.

Electron tube cathode

In a thermionic cathode having a planar emissive body and a heating element of pyrolytic graphite which is provided on the side of the emissive body remote from the emissive surface of the emissive body, a uniform temperature distribution adjusts during operation throughout the overall emissive surface when the heating element is planar and the crystallographic c-axis of the pyrolytic graphite extends everywhere normal to the surface of the heating element facing the emissive body. As a result of this the possibility is obtained of realizing a planar, 'rapid', induction-free unipotential cathode having a substantially ideal homogeneous temperature distribution.

Electron tube with pyrolytic graphite heating element

Disclosed are grid electrodes of glassy carbon which have good mechanical and electrical properties and can be manufactured in a simple manner with a great dimensional stability. The grid electrodes may be made by two alternative methods. In one method a body of cured synthetic resin is formed or processed into the shape of the desired electrode, after which it is carbonized. In the second method a preshaped body of cured synthetic resin which is in the unprocessed state, is carbonized after which the resulting glassy carbon body is further processed to the desired electrode, preferably by laser beam cutting.

Electrodes, for example grid-like electrodes for use in electron tubes,

Disclosed is a method of manufacturing a pyrolytic graphite grid electrode in which after formation of the grid, the electrode is annealed at a temperature of 700.degree. to 1200.degree. C in a reactive atmosphere to remove carbon particles adhering to the electrode surface.

Method of manufacturing grid electrodes for electron tubes

Method of manufacturing grid electrodes wherein a grid sleeve is produced by depositing pyrolytic graphite on a polished mandril of glassy carbon and provided with apertures by means of the laser beam, then the finished grid is provided, by means of hot gas pyrolysis, with a second layer of highly oriented pyrolytic graphite, and thermally and/or mechanically after-treated at 3000.degree. to 3800.degree. K and 10-500 bar.

A dispenser cathode for a grid-controlled electron tube in which the emission of surface regions immediately opposite the control grid is reduced by providing projections above the emissive surface of fused, pore-closing portons which have a focussing effect. These projections may be formed by electron beam or laser beam welding.

Growing community of inventors

Hamburg, Germany

Horst Seifert