| 摘要 |
<p>The tube is applicable to television camera tubes designed for 625 line operation but run on 312.5 line systems. The design removes the problem of local build-up of potential in the inter-line spaces in the target. The camera tube is a glass cylinder with a thin metallic layer constituting the signal plate and a photoconducting layer deposited on top of it. The electron beam is focussed by a shaped electrode of cylindrical form and two externally mounted concentric coils. A fine mesh, situated at the end of the focussing electrode, causes the electrons to slow down and to strike the target normally. The electron gun has two cathodes and two heating filaments. Either a single filament, or both can be switched on. The filaments are juxtaposed so that, in conjunction with the geometry of the beam optics, the target can either by fully scanned and/or simply have the principal lines scanned as in a 312.5 line system.</p> |
