| 摘要 |
<p>The picture display device has a display tube comprising an evacuated envelope (1) comprising a display window (2) with a display screen (3) on its inner side, a conical portion (4) and a neck portion (5). The conical portion is connected to an upstanding wall (15) of the display window. The neck portion accommodates an electron gun (6, 7, 8). The conical portion comprises a glass component. The neck portion comprises a glass component with a composition that is substantially the same as that of the conical portion. Preferably, the neck portion comprises, expressed as a percentage by weight, the following constituents: SiO 2 and Al 2 O 3 , the sum of the concentrations of SiO 2 and Al 2 O 3 being in the range from 50-65 weight%, BaO and/or SrO and/or ZrO 2 the sum of the concentrations of BaO and/or SrO and/or ZrO 2 being in the range from 0.5-10 weight%, and 10-25 weight% PbO.</p> |
