| 摘要 |
<p>1,064,989. Projection screens. MECHANISCHE WEBEREI G.m.b.H. May 15, 1964 [May 18, 1963], No.20378/64. Heading G2J. A projection screen made of a plastics foil and containing plasticizers to render it foldable and crease-resistant, and a white pigment, has material providing a high reflectivity factor normal to the screen at one or both surfaces. The material, lead carbonate crystals, may be embedded in the plastics foil or may be embedded in a second thinner layer of foil bonded to the base foil, the second foil generally being colourless. The pigment used is titanium dioxide crystals. Glass or plastics beads of high refractive index, silver or aluminium particles, or metal bronzes or spangles may be used instead of lead carbonate crystals.</p> |
