Patent ID: 6833659
Filing Date: 2004-12-21
Classification: H01J

Abstract:
A cathode ray tube provided with at least one oxide cathode comprisinga cathode carrier with a cathode base of a cathode metal and a cathode coating of an electron-emitting material containing a particle-particle composite material of oxide particles of an alkaline earth oxide selected from the group formed by the oxides of calcium, strontium and barium, and oxide particles having a first grain size distribution of an oxide selected from the group formed by the oxides of scandium, yttrium and the lanthanoids, and oxide particles having a second grain size distribution of an oxide selected from the group formed by the oxides of scandium, yttrium and the lanthanoids, characterized in that the electron-emitting material is a stratified composite of at least a first and at least a second layer, said first layer comprising the oxide particles of the alkaline earth oxide selected from the group formed by the oxides of calcium, strontium and barium, and the oxide particles having the first grain size distribution of the oxide selected from the group formed by the oxides of scandium, yttrium and the lanthanoids, and said second layer comprising the oxide particles of the alkaline earth oxide selected from the group formed by the oxides of calcium, strontium and barium, and the oxide particles having the second grain size distribution of the oxide selected from the group formed by the oxides of scandium, yttrium and the lanthenoids.