| 摘要 |
<p>In a flat cathode ray tube display apparatus a low energy, electron beam (18) is directed substantially parallel to a faceplate (12) carrying a phosphor screen (14) in a space between a deflection electrode array (22) and the input side of an electron multiplier (16) adjacent the screen where it is deflected by operation of the electrode array (22) in field scan manner towards the screen to provide a raster scanning input to the multiplier. The deflector electrodes (23) of the array are switched successively between two voltage levels in each field to step the line scanning beam with the switching voltages in successive fields differing whereby two interleaved sets of display lines are drawn in two consecutive fields which together constitute a display frame having the required number of active display lines. The voltage switching circuit (52) may be carried on a substrate adjacent the electrode array. For colour display the screen comprises a pattern of different colour phosphor elements and a selection electrode arrangement (38) is disposed adjacent the multiplier output side. Three differently coloured, and accurately superimposed, sub-lines are drawn on the screen in a standard line scan period between stepping the beam.</p> |
