| 摘要 |
826,739. Photo-sensitive devices. RADIO CORPORATION OF AMERICA. Feb. 3, 1956 [Feb. 18, 1956], No. 3468/56. Class 37. A light-sensitive element comprises a plurality of photo-conductive layers on a transparent electrode, at least one of the layers being of porous structure produced in an atmosphere of pressure of between <SP>1</SP>/ 10 and 5 millimetres of mercury. Figs. 1 and 2 show a television pickup tube having a target 13 with transparent support 21, transparent conductive member 22, porous photoconductive layer 23 and solid photoconductive layer 24. The target may be produced by spraying tin oxide or tin chloride to form layer 22, evaporating porous layer 22 in an atmosphere of argon, neon, oxygen or air of a pressure between <SP>1</SP>/ 10 and 5 mm. of Hg, and evaporating solid layer 24. The photoconductive material may consist of antimony trisulphide, cadmium selenide, or germanium sulphide. The individual layers may consist of different materials, and may be of from 0.01 to 0.4 mils. thick. The position of the solid and porous layers may be reversed, and more than two layers may be provided. |
