Colour CRT with shadow mask with improved aperture shape

摘要

The CRT has an electron gun which generates and guides several electron beams through the shadow mask (24) on to the screen. The mask has two long and two short sides, with the long ones parallel to the central main axis (X), and the short ones parallel to a central secondary axis (7). The shadow mask contains a group of apertures (36), each of rectangular shape with four sides. Two sides extend parallel to the main axis, determining the aperture height (H). The other two sides are parallel to the secondary axis, determining the aperture width. The dimensions increase from the centre to the respective sides at various rates.