| 摘要 |
In a colour display tube with a self-convergent deflection yoke and in-line gun assembly, the beams are predistorted by asymmetric beam passage apertures in electrode 23 (and see Fig. 7) before entering the main focusing lens formed between electrodes 27 and 29, which have recessed apertures common to the three beams at their juxtaposed ends, the recesses being respectively of racetrack (Fig. 4) and dogbone (Fig. 5) shape, and such that the major transverse dimension of the lens exceeds three times the spacing between adjacent apertures in each electrode 27 and 29, and the spacing between adjacent beams does not exceed 200 mils in the transverse planes through the deflection centres. The internal diameter of the deflection yoke at the exit end of its windows is less than 30 mils per degree of the deflection angle defined by diagonally opposed corners of the raster. A formula for envelope shape is disclosed (Figures 11 and 12). <IMAGE> |
