| 摘要 |
An optical element (12) has two opposite major faces (13, 14), a first (13) of which, intended to be an incident face in use, is formed with a plurality of cavities (16) which extend partway through the thickness of the body (12) of the element. Flat faces (17, 32) formed either between adjacent cavities (16) or as the bottoms of the cavities, lie parallel to the opposite major face (14) of the elements so that light incident on these surfaces, and within certain range of angles, passes through the elements substantially undeviated to provide a view to an observer. Light entering the cavities (16) is refracted and reflected so as to be diverted into a narrower range of exit angles than incident angles thereby concentrating the light. In use as "daylighting" glazing transmitted light can be concentrated in an upward direction increasing the level of illumination within a room. |
