Thomson Licensing S.a.

Thomson Licensing

Jean-Luc Ricaud

Jean-Claude Pruvost

Jean-Michel Roquais

Christian Galmiche

Philippe Arnaud

Jean Remy Adamski

Gérard Proudhon

Francois Nizery

An electrode gun for a cathode-ray tube, including at least a first electrode and a second electrode for shaping and focusing the electron beam emitted by a cathode is described. These electrodes are made of a non-oxidizing alloy whose coefficient of expansion between 20&#xb0; C. and 300&#xb0; C. lies between 4&#xd7;10/&#xb0; C. and 13&#xd7;10/&#xb0; C.

Electron gun for cathode-ray tube with improved beam shaping region

Impregnated cathode for a vacuum tube comprising an emissive part in the form of a porous pellet impregnated with a compound of alkaline earth metals; the pellet is placed in a dish made of a refractory material and covered with a porous metal foil forming the emissive surface of the cathode. Moreover, the pellet has a separation surface between a heavily impregnated zone and a zone which is not impregnated or weakly impregnated so that the said separation surface comprises at least a hollow part facing the emissive surface. By virtue of the shape of this separation surface, the lifetime of the cathode is improved.

Cathode for cathode ray tube with improved lifetime

A cathode structure for an electron gun of a cathode-ray tube having a reduced size and providing a fast cathode start-up time and excellent thermal efficiency. The cathode comprises a closed chamber consisting of a cap supporting an emitting part of the cathode and a dish-shaped skirt having an internal surface which is concave so as to reflect, by radiation, the thermal energy stored in the skirt walls, towards that region of the cap supporting the emitting part. The cathode structure also comprises filament supply leads which pass through the side walls of the skirt and connect to the filament heater contained in the closed chamber.

Cathode with optimized thermal efficiency

Cathode comprising a substrate () supporting a cathode emissive coating, comprising what is called an emissive central zone () and what is called a nonemissive peripheral zone (); according to the invention: In this way it is possible to significantly limit the drift in cut-off voltage, while still maintaining good maximum emission performance in DC mode and in pulse mode.

Oxide cathode for an electron gun, having a denser and thinner emissive zone

The oxide cathode comprises a support and an oxide layer on the latter. It furthermore includes particles of a conducting material having a first end incorporated in the support and a second end lodged in the oxide layer, so as to constitute conducting bridges passing through an interface layer forming between the support and the oxide layer. The invention also relates to a process for manufacturing such a cathode. The conducting particles make it possible to improve the electrical conductivity of the cathode, both within the oxide layer and within the interface layer.

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Dijon, France

Jean-Luc Ricaud