| 摘要 |
1496949 Colour television tubes PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 14 July 1975 [17 July 1974] 29413/75 Heading H1D In a multigun colour TV C.R.T. to allow reduction of the obstruction by a shadow mask without loss of definition the mask 7 carries electrodes forming a quadruple lens round each aperture, defocusing vertically and focusing horizontally just beyond the luminescent screen 6, to irradiate from each gun a colour phosphor vertical stripe R, G, B slightly wider than the electron impact area. The mask may comprise crossed vertical and horizontal strips 13, 14 and 11, 12, attached but insulated with glass, each set commoned and carrying a potential respectively above and below the mean mask potential. Alternatively the mask may be made from interwoven conductors insulated at their intersections (Fig. 4, not shown) or if may be an apertured plate held at phosphor screen potential (e.g. Fe for magnetic screening) (Fig. 6 not shown) carrying between the apertures a set of vertical strips (e.g. vapour deposited Al) at a lower potential or isolated and charged by the electron beams to reach a stable equilibrium potential. In all embodiments secondary electron effects are negligible. |
