A new layer system of anti-reflective coating for cathode ray tubes

• Published in: Thin solid films 1999-08, Vol.351 (1-2), p.235-240
• Main Authors: OYAMA, T, OHSAKI, H, TACHIBANA, Y, HAYASHI, Y, ONO, Y, HORIE, N
• Format: Article
• Language: English
• Subjects: Exact sciences and technology; Fundamental areas of phenomenology (including applications); Optical coatings; Optical elements, devices, and systems; Optics; Physics
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/S0040-6090(99)00214-X

A new anti-reflective (AR) coating system, using an absorbing layer, has been developed for cathode ray tubes (CRTs). Theoretical analysis has revealed that the basic system needs only two layers to achieve zero reflection throughout the visible region if an ideal absorbing layer and a transparent layer are combined. The conditions for realizing the ideal AR property with two-layer system has been derived by numerical calculations. TiN sub(x)O sub(y) was chosen as the actual absorbing layer, while SiO sub(2) was chosen as the transparent layer. These choices are both based on theoretical and experimental considerations. The oxygen content in the TiN sub(x)O sub(y) film was found to play an important role on the AR properties, therefore a very thin (around 5 nm) SiN sub(x) barrier layer was deposited on the TiN sub(x)O sub(y) layer to prevent the oxidization of the TiN sub(x)O sub(y) during the subsequent deposition of SiO sub(2). The insertion of such a thin SiN sub(x) layer was found to have almost no influence on the optical properties, therefore the system (Glass/TiN sub(x)O sub(y)/SiN sub(x)/SiO sub(2)) can be called as two-layer system with a barrier layer. The AR properties and the electromagnetic shielding property (i.e. the electrical conductivity) of the coating was almost the same as the conventional transparent multilayer system which needs more than twice as thick as this system. This coating has been successfully adapted to the panel glass for CRTs on an industrial scale.