Abstract An electron scattering prevention film in disclosed comprising at least the following three layers: an electrode layer deposited on a phosphor layer; a first electron scattering prevention layer deposited on the electrode layer composed of a first electron scattering prevention material having a smaller atomic number than that of the material constituting the electrode layer; and a second electron scattering prevention layer deposited on the first electron scattering prevention layer composed of a second electron scattering prevention material having a smaller atomic number than that of the material constituting the electrode layer. A bimetal action which occurs between the electrode layer and the first electron scattering prevention layer is cancelled by a bimetal action which occurs between the first electron scattering prevention layer and the second electron scattering prevention layer whereby the electron scattering prevention film is prevented from being distorted to an extent that the electrode layer peels off from the phosphor layer under variation of temperature.
The electron scattering-prevention fiLm as defined in claim 1 wherein the respective thicknesses of the metallic electrode layer and the first and second electron scattering-prevention layers satisfy a relationship expressed by or approximated by the following equation: t''b(l + t''b)( Alpha a - Alpha b) EaEb + t''bt''c(t''b + t''c)( Alpha b - Alpha c) EbEc - t''c(l - 2t''b + t''c)( Alpha c - Alpha a)EcEa 0 where t''b tb/ta'', t''c tc/ta; ta, tb and tc are thicknesses respectively of the metallic electrode layer, the first electron scattering-prevention layer; Alpha a, Alpha b and Alpha c are coefficients of thermal expansion, and Ea, Eb and Ec are Young''s moduluses respectively of the metal of the electrode layer, the first compound and the second compound.
Claim 2
Dependent Claim
64 words
The electron scattering-prevention film as defined in claim 1 further comprising a third electron scattering-prevention layer deposited on said second electron scattering-prevention layer, said third electron scattering-prevention layer being of the same compound as the first compound, and a fourth electron scattering-prevention layer deposited on said third electron scattering-prevention layer, said fourth electron scattering-prevention layer being of the same compound as the second compound.
Claim 3
Dependent Claim
34 words
The electron scattering-prevention film as defined in claim 1 wherein the metal of the electrode layer is aluminum (Al), the first compound is boron carbide (B4C) and the second compound is lithium fluoride (LiF).