| 摘要 |
922,847. Light transmitting panels. CORNING GLASS WORKS. May 5, 1960 [May 13, 1959], No. 15965/60. Drawings to Specification. Class 75 (2). [Also in Group XXIII] A light transmitting panel has refracting prisms formed on at least one surface and a small number of light diffusing particles, at least sufficient to diffuse stray light emitted at high angles, dispersed throughout the panel. The prisms may be designed to concentrate the light into preferred zones and the diffusing particles serve to produce a zone of diminished brightness between the zones of concentrated and reduced transmission. The panel may contain uniformly dispersed crystallites in a concentration of 150-1000 per c. mm. The size of the crystallites may vary from 0.01 to 0.25 mm. For example, at 1000 crystallites per c. mm., 28% may be over 0.01 mm. and 2% over 0.08 mm. and at 150 crystallites per c. mm. 53% may be over 0.01 mm. and 6% over 0.08 mm. A suitable glass contains 60% SiO 2 , 10% Al 2 O 3 10% BaO and 15% Na 2 O, the balance including 2-3% sulphate, calculated as SO 3 , for particle formation, 0.5-1.5% arsenic oxide to promote crystallite formation and 0.5-1.0% TiO 2 . Alternatively, insoluble particles, e.g. of talc may be incorporated in a glass or plastic mass from which the panels are produced. Specifications 619,084 and 879,153 are referred to. |
