| 摘要 |
<p>Temporary restriction of the transmission areas in grid coatings applied to CRT's by loading the grids with an alcholic soln. of PVA which can be dried to create meniscus bridges across each cell of the grid. The soln. is loaded with an additive which absorbs radiation in the range 350-380 nm, the loading being such that the relatively thin (1 mu) central regions of each meniscus are traversed by some of the radiation, but the boundary regions of the meniscus are effectively opaque. Pref. 6-8% wt. OVA is dissolved in a 50:50 mixt. of water with cH3OH or C2H5OH together with UV absorbent predispersed in CH3OH or C2H5OH so that the coating mixt. has an initial viscosity of 60-100 cP. For selectively restricting window areas for certain regions or proportions of the phosphor screens to improve contrast and definition. The screening effect obtd. can be finely adjusted and reproducibly and uniformly generated by use of appropriate concns. and deposition patterns. The meniscus can subsequently be leached off.</p> |
