| 摘要 |
1,192,246. Luminescent screens. TEXAS INSTRUMENTS Inc. 28 June, 1967 [30 June, 1966], No. 29877/67. Heading C4S. [Also in Divisions C1 and H1] A method of increasing the electron energization threshold of phosphor particles (e.g. ZnS-CdS: Ag) comprises heating same to elevated temperatures (e.g. 400‹ to 685‹ C.) and exposing to an atmosphere (e.g. dry or wet oxygen within He 1 N 2 or A) which reacts in vapour phase with the particle surfaces to form an electron retarding barrier layer (e.g. of ZnO). The particles are subsequently heated and exposed to an atmosphere of sulphurcontaining material (e.g. sulphur or hydrogen sulphate) which reacts in vapour phase with the particle surfaces to effect conversion to sulphide-containing electron barrier layers. Viewing screens incorporating the above particles may be included in two colour (red and cyan or green) and three colour (red, cyan and blue) T.V. display systems wherein 16 to 20 micron diameter phosphor particles may be randomly mixed in a mono particle thick layer or each phosphor particle type of different electron energization thresholds may be in separate layers superimposed, the energy of the electron beam being modulated according to the colour output required. The particles of the lowest energy threshold may or may not have a barrier layer. |
