| 摘要 |
1,071,963. Cathode-ray tubes. SONY CORPORATION. Aug. 19, 1964 [Aug. 19, 1963], No. 33893/64. Heading H1D. A post-deflection focusing cathode-ray tube having a colour switching grid of parallel wires adjacent its screen, held at such a potential as to produce a focusing action, includes also an electrode located close to and around the edge of the grid, and maintained at such a potential, dependent upon its spacing from the grid, that the focusing action-and hence the spot sizeis uniform over the surface of the screen, and the spot size is a minimum with respect to the electrode potential. A frame 20 (Fig. 6, not shown) mounted in front of a screen composed of multi-coloured phosphor stripes (10) and an aluminium coating (12), supports a grid of parallel wires (11) extending across the screen (Fig. 2, not shown) and cemented to the frame (at 27), together with a shielding and decelerating electrode (13) and an additional electrode (26), which is insulated from the frame and is held at such a potential as to counteract the defocussing effect of the adjacent frame upon electrons passing between the wires of the grid near its edge. Electrode (26) also shields the frame from impact by the electron beam when deflected off the screen. |
