| 摘要 |
A reflective diffuser of light in one embodiment comprises an extruded, drawn, rolled or otherwise stretched or extended sheet comprising a matrix of a first plastics material incorporating inclusions of a second, different material, substantially insoluble in the first material, resulting in small scale surface irregularities on at least one surface of the sheet. The textured surface having such irregularities is rendered reflective or partly reflective, for example by metallisation, eg. by vapour deposition or other particle deposition of metal, such as vacuum sputtering. By controlling the extent to which the sheet is stretched preferentially in one direction during manufacture, the extent to which the diffuser has asymmetric diffusing properties can be readily controlled. Instead of metallising the extended sheet itself, the textured surface of the latter may be used as a mould or die surface for the production of a textured surface on another, eg. plastics sheet which may then be metallised or the textured surface of the extended sheet may be used as the progenitor of a mould or die surface for the production of such plastics sheets bound for metallisation to form reflective diffusers. Reflective light diffusers according to the invention may be used, for example, in LCD displays as back reflectors. |
