Patent ES-8603111-A1 (ES)
Title: A cathode ray tube and an electron multiplying structure therefor.
IPC: H01J43/22
Filed: 1985-02-05
Abstract: The structure is disposed between an electron producer and a cathodoluminescent screen. The structure includes a stack of N-apertured planar dynodes sepd. from each other by spacers and arranged in cascade with the apertures in adjacent dynodes being aligned to form channels. - The second to the (n-1)th dynodes has the apertures each with a re-entrant portion (24) within the thickness of the dynode. The axially spaced ends (26,28) of the re-entrant portion are spaced from the respective opposite surfaces of the dynode by an input portion (20) and an output portion (22). The cross-sections of the axially spaced ends of the re-entrant portion which communicate with the input and output portions, respectively, are smaller than a cross-section between the axially spaced ends. (2/6) EPAB- EP-151502 B The structure is disposed between an electron producer and a cathodoluminescent screen. The structure includes a stack of N-apertured planar dynodes sepd. from each other by spacers and arranged in cascade with the apertures in adjacent dynodes being aligned to form channels. - The second to the (n-1)th dynodes has the apertures each with a re-entrant portion (24) within the thickness of the dynode. The axially spaced ends (26,28) of the re-entrant portion are spaced from the respective opposite surfaces of the dynode by an input portion (20) and an output portion (22). The cross-sections of the axially spaced ends of the re-entrant portion which communicate with the input and output portions, respectively, are smaller than a cross-section between the axially spaced ends. (16pp Dwg.No.2/6) - EP-151502 B A cathode ray tube (40) comprising an envelope within which is provided a channel plate electron multiplying structure (42) disposed between electron producing means (44) and a cathodoluminescent screen (50), the electron multiplying structure (42) comprising a stack of n dynodes (10), each dynode having the form of a plate bounded by first and second parallel, substantially planar surfaces and having an array of secondary-electron emissive through-apertures whereby electrons are incident on the first or input, planar surface and secondary electrons emerge from the aperture at the second, or output planar surface, the dynodes (10) being accurately sepd. from each other in parallel relationship and being arranged in cascade, with the apertures in adjacent dynodes being aligned to form channels permitting the passage of electrons, the dynodes (10) being numbered from 1 (on which electrons from an external source impinge) to n, characterised in that in at least the second to the (n-1)th dynodes (10) the apertures therein each have a re-entrant portion (24) within the thickness of the dynode and are in any cross-section thereof by a plane parallel to the plane of the dynode substantially circular or square, the axially spaced ends of the re-entrant portion (24) being spaced from the respective adjacent surfaces of the dynode by an input portion (20) and an output portion (22), the cross-sectional areas of the axially spaced ends of the re-entrant portion which communicate with the input and output portions (20,22) respectively, being smaller than any cross-sectional area between the axially spaced ends and in that the transverse dimensions of the axially spaced ends of each aperture are substantially equal to one another and the axial length (T) of the re-entrant portion (24) and at most substantially equal to the minimum transverse dimension of the input and output portions (20,22). (11pp) USAB- US4626736 A The ray tube comprises a channel plate electron multiplier structure between a source of electrons and cathodeoluminescent screen. The electron multiplier comprises a stack of n apertured dynodes which are separated from each other and are arranged in cascade with the apertures in adjacent dynodes aligned to form channels. - A re-entrant portion within the thickness of the dynode with the axially spaced ends of the re-entrant portion is spaced from the respective opposite surfaces of the dynode by a convergent or cylindrical input portion and a divergent or cylindrical output portion. The axial length of the re-entrant portion corresponds substantially to the cross-section of the input (or output) portion at a point where it communicates with the re-entrant portion.